Hurricane Katrina

On August 19, 2005, a weak tropical wave combined with the mid-level remnants of Tropical Depression Ten and an upper tropospheric trough near the Lesser Antilles. On August 23, this disturbance organized into Tropical Depression Twelve over the southeastern Bahamas. The storm strengthened into Tropical Storm Katrina on the morning of August 24. The tropical storm moved towards Florida and became a hurricane only two hours before making landfall between Hallandale Beach and Aventura on the morning of August 25. The storm weakened over land, but it regained hurricane status about one hour after entering the Gulf of Mexico, and it continued strengthening over open waters. On August 27, the storm reached Category 3 intensity on the Saffir–Simpson hurricane wind scale, becoming the third major hurricane of the season. An eyewall replacement cycle disrupted the intensification but caused the storm to nearly double in size. Thereafter, Katrina rapidly intensified over the "unusually warm" waters of the Loop Current, from a Category 3 hurricane to a Category 5 hurricane in just nine hours.

After attaining Category 5 hurricane status on the morning of August 28, Katrina reached its peak strength at 1800 UTC, with maximum sustained winds of 175 mph (280 km/h) and a minimum central pressure of 902 mbar (26.64 inHg). The pressure measurement made Katrina the fifth most intense Atlantic hurricane on record at the time, only to be surpassed by Hurricanes Rita and Wilma later in the season; it was also the strongest hurricane ever recorded in the Gulf of Mexico at the time, before Rita broke the record. The hurricane subsequently weakened due to another eyewall replacement cycle, and Katrina made its second landfall at 1110 UTC on August 29, as a high-end Category 3 hurricane with sustained winds of 125 mph (201 km/h), near Buras-Triumph, Louisiana. At landfall, hurricane-force winds extended outward 120 miles (190 km) from the center and the storm's central pressure was 920 mbar (27 inHg). After moving over southeastern Louisiana and then Breton Sound, it made its third and final landfall near the Louisiana–Mississippi border, with Category 3 sustained winds of 120 mph (195 km/h). Katrina maintained hurricane strength well into Mississippi, finally weakening to tropical storm strength more than 150 miles (240 km) inland near Meridian, Mississippi. It was downgraded to a tropical depression near Clarksville, Tennessee; its remnants were absorbed by a cold front in the eastern Great Lakes region on August 31. The resulting extratropical storm moved rapidly to the northeast and affected eastern Canada before finally dissipating off the eastern coast of Greenland on September 7.

=== Federal government ===

The United States Coast Guard began pre-positioning resources in a ring around the expected impact zone and activated more than 400 reservists. On August 27, it moved its personnel out of the New Orleans region prior to the mandatory evacuation. Aircrews from the Aviation Training Center, in Mobile, staged rescue aircraft from Texas to Florida. All aircraft were returning towards the Gulf of Mexico by the afternoon of August 29. Aircrews, many of whom lost their homes during the hurricane, began a round-the-clock rescue effort in New Orleans, and along the Mississippi and Alabama coastlines.

President George W. Bush declared a state of emergency in selected regions of Louisiana, Alabama, and Mississippi on August 27. "On Sunday, August 28, President Bush spoke with Governor Blanco to encourage her to order a mandatory evacuation of New Orleans." However, during the testimony by former Federal Emergency Management Agency (FEMA) chief Michael Brown before a U.S. House subcommittee on September 26, Representative Stephen Buyer (R-IN) inquired as to why Bush's declaration of state of emergency of August 27 had not included the coastal parishes of Orleans, Jefferson, and Plaquemines. The declaration actually did not include any of Louisiana's coastal parishes, whereas the coastal counties were included in the declarations for Mississippi and Alabama. Brown testified that this was because Louisiana Governor Blanco had not included those parishes in her initial request for aid, a decision that he found "shocking". After the hearing, Blanco released a copy of her letter, which showed she had requested assistance for "all the southeastern parishes including the City of New Orleans" as well as specifically named 14 parishes, including Jefferson, Orleans, St. Bernard, and Plaquemines.

Voluntary and mandatory evacuations were issued for large areas of southeast Louisiana as well as coastal Mississippi and Alabama. About 1.2 million residents of the Gulf Coast were covered under a voluntary or mandatory evacuation order.

On the afternoon of August 26, the National Hurricane Center (NHC) realized that Katrina had yet to make the turn toward the Florida Panhandle and ended up revising the predicted track of the storm from the panhandle to the Mississippi coast. The National Weather Service's New Orleans/Baton Rouge office issued a vividly worded bulletin on August 28 predicting that the area would be "uninhabitable for weeks" after "devastating damage" caused by Katrina, which at that time rivaled the intensity of Hurricane Camille. During video conferences involving the president later that day and on August 29, NHC director Max Mayfield expressed concern that Katrina might push its storm surge over the city's levees and flood walls. In one conference, he stated, "I do not think anyone can tell you with confidence right now whether the levees will be topped or not, but that's obviously a very, very great concern."

==== Florida ====

In Florida, Governor Jeb Bush declared a state of emergency on August 24 in advance of Hurricane Katrina's landfall. By the following day, Florida's Emergency Operations Center was activated in Tallahassee to monitor the progress of the hurricane. Before Katrina moved ashore, schools and businesses were closed in the Miami area. Cruise ships altered their paths due to seaports in southeastern Florida closing. Officials in Miami-Dade County advised residents in mobile homes or with special needs to evacuate. To the north in Broward County, residents east of the Intracoastal Waterway or in mobile homes were advised to leave their homes. Evacuation orders were issued for offshore islands in Palm Beach County, and for residents in mobile homes south of Lantana Road. Additionally, a mandatory evacuation was ordered for vulnerable housing in Martin County. Shelters were opened across the region. Officials closed the Miami International Airport, Fort Lauderdale–Hollywood International Airport, Key West International Airport, and Florida Keys Marathon Airport due to the storm. In Monroe and Collier counties, schools were closed, and a shelter was opened in Immokalee.

On August 28, Alabama Governor Bob Riley declared a state of emergency for the approaching Hurricane Katrina. On the same day, he requested President Bush to declare "expedited major disaster declaration" for six counties of South Alabama, which was quickly approved. Three hundred fifty national guardsmen were called on duty by August 30. The state of Mississippi activated its National Guard on August 26 in preparation for the storm's landfall. Additionally, the state government activated its Emergency Operations Center the next day, and local governments began issuing evacuation orders. By 6:00 p.m. CDT on August 28, 11 counties and cities issued evacuation orders, a number which increased to 41 counties and 61 cities by the following morning. Moreover, 57 emergency shelters were established on coastal communities, with 31 additional shelters available to open if needed.

By Sunday, August 28, most infrastructure along the Gulf Coast had been shut down, including all freight and Amtrak rail traffic into the evacuation areas as well as the Waterford Nuclear Generating Station. Since Hurricane Katrina, Amtrak's Sunset Limited service has never been restored past New Orleans.

In Louisiana, the state's hurricane evacuation plan calls for local governments in areas along and near the coast to evacuate in three phases, starting with the immediate coast 50 hours before the start of tropical-storm-force winds. Persons in areas designated Phase II begin evacuating 40 hours before the onset of tropical storm winds and those in Phase III areas (including New Orleans) evacuate 30 hours before the start of such winds. Many private caregiving facilities that relied on bus companies and ambulance services for evacuation were unable to evacuate their charges because they waited too long. Louisiana's Emergency Operations Plan Supplement 1C (Part II, Section II, Paragraph D) calls for use of school and other public buses in evacuations. Although buses that later flooded were available to transport those dependent on public transportation, not enough bus drivers were available to drive them since Governor Blanco did not sign an emergency waiver to allow any licensed driver to transport evacuees on school buses.

By August 26, many of the computer models had shifted the potential path of Katrina 150 miles (240 km) westward from the Florida Panhandle, putting the city of New Orleans directly in the center of their track probabilities; the chances of a direct hit were forecast at 17%, with strike probability rising to 29% by August 28. This scenario was considered a potential catastrophe because some parts of New Orleans and the metro area sit below sea level. Since the storm surge produced by the hurricane's right-front quadrant (containing the strongest winds) was forecast to be 28 feet (8.5 m), while the levees offered protection to 23 feet (7.0 m), emergency management officials in New Orleans feared that the storm surge could go over the tops of levees protecting the city, causing major flooding.

At a news conference at 10 a.m. EDT on August 28, shortly after Katrina was upgraded to a Category 5 storm, New Orleans mayor Ray Nagin ordered the first-ever mandatory evacuation of the city, calling Katrina "a storm that most of us have long feared". The city government also established several "refuges of last resort" for citizens who could not leave the city, including the massive Louisiana Superdome, which sheltered approximately 26,000 people and provided them with food and water for several days as the storm came ashore. Some estimates claimed that 80% of the 1.3 million residents of the greater New Orleans metropolitan area evacuated, leaving behind substantially fewer people than remained in the city during the Hurricane Ivan evacuation.

On August 29, 2005, Katrina's storm surge caused 53 breaches to various flood protection structures in and around the greater New Orleans area, submerging 80% of the city. A June 2007 report by the American Society of Civil Engineers indicated that two-thirds of the flooding was caused by the multiple failures of the city's floodwalls. The storm surge also devastated the coasts of Mississippi and Alabama, making Katrina one of the most costly natural disasters in the history of the United States and the deadliest hurricane since the 1928 Okeechobee hurricane. The total damage from Katrina is estimated at $125 billion (2005 U.S. dollars).

The death toll from Katrina is uncertain, with reports differing by hundreds. The NHC originally attributed 1,836 fatalities to the storm: one in Kentucky, two each in Alabama, Georgia, and Ohio, 14 in Florida, 238 in Mississippi, and 1,577 in Louisiana. However, 135 people remain categorized as missing in Louisiana, and many of the deaths are indirect, but it is almost impossible to determine the exact cause of some of the fatalities. A 2008 report by the Disaster Medicine and Public Health Preparedness journal indicates that 966 deaths can be directly attributed to the storm in Louisiana, including out of state evacuees, and another 20 indirectly (such as firearm-related deaths and gas poisoning). Due to uncertain causes of death with 454 evacuees, an upper-bound of 1,440 is noted in the paper. A follow-up study by the Louisiana Department of Health & Hospitals determined that the storm was directly responsible for 1,170 fatalities in Louisiana. On January 4, 2023, the NHC updated the Katrina fatality data on the basis of a 2014 report, which reduced the total number from an estimated 1,833 to 1,392.

Federal disaster declarations covered 90,000 square miles (230,000 km2) of the United States, an area almost as large as the United Kingdom. The hurricane left an estimated three million people without electricity. On September 3, 2005, Homeland Security Secretary Michael Chertoff described the aftermath of Hurricane Katrina as "probably the worst catastrophe or set of catastrophes" in the country's history, referring to the hurricane itself plus the flooding of New Orleans.

Even in 2010, debris remained in some coastal communities.

Before striking South Florida, Katrina traversed the Bahamas as a tropical storm. However, minimal impact was reported, with only "fresh breezes" on various islands.

Although Hurricane Katrina stayed well to the north of Cuba, on August 28 it brought tropical-storm-force winds and rainfall of over 8 in (200 mm) to western regions of the island. Telephone and power lines were damaged and around 8,000 people were evacuated in the Pinar del Río Province. According to Cuban television, the coastal town of Surgidero de Batabanó was 90% underwater.

==== Florida ====

Hurricane Katrina first made landfall between Hallandale Beach and Aventura, Florida on August 25. The storm dropped heavy rainfall in portions of the Miami metropolitan area, with a peak total of 16.43 in (417 mm) in Perrine. As a result, local flooding occurred in Miami-Dade County, damaging approximately 100 homes. Farther south in the Florida Keys, a tornado was spawned in Marathon on August 26. The tornado damaged a hangar at the airport there and caused an estimated $5 million in damage. The rains caused flooding, and the combination of rains and winds downed trees and power lines, leaving 1.45 million people without power. Damage in South Florida was estimated at $523 million, mostly as a result of crop damage. Twelve deaths occurred in South Florida, of which three were caused by downed trees in Broward County, three from drowning in Miami-Dade County, three were from carbon monoxide poisoning caused by generators, one was due to a vehicle accident, one occurred during debris cleanup, and one was associated with a lack of electricity.

Significant impacts were also reported in the Florida Panhandle. Although Katrina moved ashore in Louisiana and Mississippi, its outer periphery produced a 5.37 ft (1.64 m) storm surge in Pensacola. High waves caused beach erosion and closed nearby roadways. There were five tornadoes in the northwestern portion of the state, though none of them caused significant damage. Throughout the Florida Panhandle, the storm resulted in an estimated $100 million in damage. There were two indirect fatalities from Katrina in Walton County as a result of a traffic accident. In the Florida Panhandle, 77,000 customers lost power. Overall, the hurricane killed 14 people and caused at least $623 million in damage.

On August 29, 2005, Hurricane Katrina made landfall near Buras-Triumph, Louisiana, with 125 mph (200 km/h) winds, as a strong Category 3 hurricane. Although the storm surge to the east of the path of the eye in Mississippi was higher, a significant surge affected the Louisiana coast. The height of the surge is uncertain because of a lack of data, although a tide gauge in Plaquemines Parish indicated a storm tide in excess of 14 feet (4.3 m), and a 12-foot (3.7 m) storm surge was recorded in Grand Isle. The hurricane made its final landfall near the mouth of the Pearl River, with the eye straddling St. Tammany Parish, Louisiana, and Hancock County, Mississippi, on the morning of August 29 at about 9:45 am. CDT.

Hurricane Katrina also brought heavy rain to Louisiana, with 8–10 inches (200–250 mm) falling on a wide swath of the eastern part of the state. In the area around Slidell, the rainfall was even higher, and the highest rainfall recorded in the state was approximately 15 inches (380 mm). As a result of the rainfall and storm surge the level of Lake Pontchartrain rose and caused significant flooding along its northeastern shore, affecting communities from Slidell to Mandeville. Several bridges were destroyed, including the I-10 Twin Span Bridge connecting Slidell to New Orleans. Almost 900,000 people in Louisiana lost power as a result of Hurricane Katrina.

Katrina's storm surge inundated all parishes surrounding Lake Pontchartrain, including St. Tammany, Tangipahoa, St. John the Baptist, and St. Charles Parishes. St. Tammany Parish received a two-part storm surge. The first surge came as Lake Pontchartrain rose and the storm blew water from the Gulf of Mexico into the lake. The second came as the eye of Katrina passed, westerly winds pushed water into a bottleneck at the Rigolets Pass, forcing it farther inland. The range of surge levels in eastern St. Tammany Parish is estimated at 13–16 feet (4.0–4.9 m), not including wave action.

Hard-hit St. Bernard Parish was flooded because of breaching of the levees that contained a navigation channel called the Mississippi River Gulf Outlet (MR-GO.) The search for the missing was undertaken by the St. Bernard Fire Department because of the assets of the United States Coast Guard being diverted to New Orleans. In the months after the storm, many of the missing were tracked down by searching flooded homes, tracking credit card records, and visiting homes of family and relatives.

According to the U.S. Dept. of Housing and Urban Development, in St. Bernard Parish, 81% (20,229) of the housing units were damaged. In St. Tammany Parish, 70% (48,792) were damaged and in Plaquemines Parish 80% (7,212) were damaged.

In addition, the combined effect of Hurricanes Katrina and Rita was the destruction of an estimated 562 square kilometres (217 sq mi) of coastal wetlands in Louisiana.

As the eye of Hurricane Katrina swept to the northeast, it subjected the city to hurricane conditions for hours. Although power failures prevented accurate measurement of wind speeds in New Orleans, there were a few measurements of hurricane-force winds; based on this information, the NHC concluded that much of the city likely experienced sustained winds of Category 1 or 2 hurricane strength.

Katrina's storm surge caused 53 levee breaches in the federally built levee system protecting metro New Orleans and the failure of the 40 Arpent Canal levee. Failures occurred in New Orleans and surrounding communities, especially St. Bernard Parish. The Mississippi River Gulf Outlet (MR-GO) breached its levees in approximately 20 places, flooding much of eastern New Orleans, most of St. Bernard Parish and the East Bank of Plaquemines Parish. The major levee breaches in the city included breaches at the 17th Street Canal levee, the London Avenue Canal, and the wide, navigable Industrial Canal, which left approximately 80% of the city flooded.

Most of the major roads traveling into and out of the city were damaged. The only major intact highway routes out of the city were the westbound Crescent City Connection and the Huey P. Long Bridge, as large portions of the I-10 Twin Span Bridge traveling eastbound towards Slidell, Louisiana had collapsed. Both the Lake Pontchartrain Causeway and the Crescent City Connection only carried emergency traffic. However, access to downtown New Orleans and the "shelter of last resort" at the Convention Center was never closed because River Road in Jefferson Parish and Leake Avenue and Tchoupitoulas Street in New Orleans were not flooded, and would have allowed access throughout the immediate post-storm emergency period.

On August 29, at 7:40 am. CDT, it was reported that most of the windows on the north side of the Hyatt Regency New Orleans had been blown out, and many other high rise buildings had extensive window damage. The Hyatt was the most severely damaged hotel in the city, with beds reported to be flying out of the windows. Insulation tubes were exposed as the hotel's glass exterior was completely sheared off.

Katrina's wind combined with water from the floodwall breaches was damaging the communication infrastructure that local law enforcement, political leaders and emergency managers in Baton Rouge and Washington relied on. Electricity was now out, landlines and telephone switching stations were being submerged. Some cell towers had lost power while others had been knocked over. "One by one, police, city, state, and federal agencies were going blind." More than 1000 base station sites were impacted. Some base stations had their own back-up generators but the long duration of power outages exceeded their capabilities. Eight days after the storm, BellSouth Corp. estimated it could take four to six months to restore service in New Orleans.

The Superdome, which was sheltering many people who had not evacuated, sustained significant damage. Two sections of the Superdome's roof were compromised and the dome's waterproof membrane was essentially peeled off. Louis Armstrong New Orleans International Airport was closed before the storm but did not flood. On August 30, it was reopened to humanitarian and rescue operations. Limited commercial passenger service resumed at the airport on September 13 and regular carrier operations resumed in early October.

Levee breaches in New Orleans also caused a significant number of deaths, with over 700 bodies recovered in New Orleans by October 23, 2005. Some survivors and evacuees reported seeing dead bodies lying in city streets and floating in still-flooded sections, especially in the east of the city. The advanced state of decomposition of many corpses, some of which were left in the water or sun for days before being collected, hindered efforts by coroners to identify many of the dead.

The first deaths reported from the city were reported shortly before midnight on August 28, as three nursing home patients died during an evacuation to Baton Rouge, most likely from dehydration. An estimated 215 bodies were found in nursing homes and hospitals in New Orleans, the largest number being at Memorial Medical Center where 45 corpses were recovered. Some 200 patients at Charity Hospital were not evacuated until Friday, September 2, having been without power or fresh water for five days. While there were also early reports of fatalities amid mayhem at the Superdome, only six deaths were confirmed there, with four of these originating from natural causes, one from a drug overdose, and one a suicide. At the Convention Center, four bodies were recovered. One of the four is believed to be the result of a homicide.

There is evidence that many prisoners were abandoned in their cells during the storm, while the guards sought shelter. Hundreds of prisoners were later registered as "unaccounted for".

The Gulf coast of Mississippi suffered extremely severe damage from the impact of Hurricane Katrina on August 29, leaving 238 people dead, 67 missing, and billions of dollars in damage: bridges, barges, boats, piers, houses, and cars were washed inland. Katrina traveled up the entire state; as a result, all 82 counties in Mississippi were declared disaster areas for federal assistance, 47 for full assistance.

After making a brief initial landfall in Louisiana, Katrina had made its final landfall near the state line, and the eyewall passed over the cities of Bay St. Louis and Waveland as a Category 3 hurricane with sustained winds of 120 mph (190 km/h). Katrina's powerful right-front quadrant passed over the west and central Mississippi coast, causing a powerful 27-foot (8.2 m) storm surge, which penetrated 6 miles (10 km) inland in many areas and up to 12 miles (19 km) inland along bays and rivers; in some areas, the surge crossed Interstate 10 for several miles. Hurricane Katrina brought strong winds to Mississippi, which caused significant tree damage throughout the state. The highest unofficial reported wind gust recorded from Katrina was one of 135 mph (217 km/h) in Poplarville, in Pearl River County.

The storm also brought heavy rains with 8–10 inches (200–250 mm) falling in southwestern Mississippi and rain in excess of 4 inches (100 mm) falling throughout the majority of the state. Katrina caused eleven tornadoes in Mississippi on August 29, some of which damaged trees and power lines.

Battered by wind, rain and storm surge, some beachfront neighborhoods were completely leveled. Preliminary estimates by Mississippi officials calculated that 90% of the structures within half a mile of the coastline were completely destroyed, and that storm surges traveled as much as 6 miles (10 km) inland in portions of the state's coast. One apartment complex with approximately thirty residents seeking shelter inside collapsed. More than half of the 13 casinos in the state, which were floated on barges to comply with Mississippi land-based gambling laws, were washed hundreds of yards inland by waves.

A number of streets and bridges were washed away. On U.S. Highway 90 along the Mississippi Gulf Coast, two major bridges were completely destroyed: the Bay St. Louis–Pass Christian bridge and the Biloxi–Ocean Springs bridge. In addition, the eastbound span of the I-10 bridge over the Pascagoula River estuary was damaged. In the weeks after the storm, with the connectivity of the coastal U.S. Highway 90 shattered, traffic traveling parallel to the coast was reduced first to State Road 11 (parallel to I-10) then to two lanes on the remaining I-10 span when it was opened.

All three coastal counties of the state were severely affected by the storm. Katrina's surge was the most extensive, as well as the highest, in the documented history of the United States; large portions of Hancock, Harrison, and Jackson counties were inundated by the storm surge, in all three cases affecting most of the populated areas. Surge covered almost the entire lower half of Hancock County, destroying the coastal communities of Clermont Harbor and Waveland, much of Bay St. Louis, and flowed up the Jourdan River, flooding Diamondhead and Kiln. In Harrison County, Pass Christian was completely inundated, along with a narrow strip of land to the east along the coast, which includes the cities of Long Beach and Gulfport; the flooding was more extensive in communities such as D'Iberville, which borders Back Bay. Biloxi, on a peninsula between the Back Bay and the coast, was particularly hard hit, especially the low-lying Point Cadet area. In Jackson County, storm surge flowed up the wide river estuary, with the combined surge and freshwater flooding cutting the county in half. Remarkably, over 90% of Pascagoula, the easternmost coastal city in Mississippi, and about 75 miles (120 km) east of Katrina's landfall near the Louisiana-Mississippi border was flooded from storm surge at the height of the storm. Other large Jackson County neighborhoods such as Porteaux Bay and Gulf Hills were severely damaged with large portions being completely destroyed, and St. Martin was hard hit; Ocean Springs, Moss Point, Gautier and Escatawpa also suffered major surge damage.

Mississippi Emergency Management Agency officials also recorded deaths in Forrest, Hinds, Warren, and Leake counties. Over 900,000 people throughout the state experienced power outages.

Although Hurricane Katrina made landfall well to the west, Alabama and the Florida Panhandle were both affected by tropical-storm-force winds and a storm surge varying from 12 to 16 feet (3.7–4.9 m) around Mobile Bay, with higher waves on top. Sustained winds of 67 mph (108 km/h) were recorded in Mobile, Alabama, and the storm surge there was approximately 12 feet (3.7 m). The surge caused significant flooding several miles inland along Mobile Bay. Four tornadoes were also reported in Alabama. Ships, oil rigs, boats and fishing piers were washed ashore along Mobile Bay: the cargo ship M/V Caribbean Clipper and many fishing boats were grounded at Bayou La Batre.

An oil rig under construction along the Mobile River broke its moorings and floated 1.5 miles (2.4 km) northwards before striking the Cochrane Bridge just outside Mobile. No significant damage resulted to the bridge and it was soon reopened. The damage on Dauphin Island was severe, with the surge destroying many houses and cutting a new canal through the western portion of the island. An offshore oil rig also became grounded on the island. As in Mississippi, the storm surge caused significant beach erosion along the Alabama coastline. More than 600,000 people lost power in Alabama as a result of Hurricane Katrina and two people died in a traffic accident in the state. Residents in some areas, such as Selma, were without power for several days.

Northern and central Georgia were affected by heavy rains and strong winds from Hurricane Katrina as the storm moved inland, with more than 3 inches (76 mm) of rain falling in several areas. At least 18 tornadoes formed in Georgia on August 29, 2005, the most on record in that state for one day in August. The most serious of these tornadoes was an F2 tornado which affected Heard County and Carroll County. This tornado caused three injuries and one fatality and damaged several houses. The other tornadoes caused significant damages to buildings and agricultural facilities. In addition to the fatality caused by the F2 tornado, there was another fatality in a traffic accident.

Eastern Arkansas received light rain from the passage of Katrina. Gusty winds downed some trees and power lines, though damage was minimal. Katrina also caused a number of power outages in many areas, with over 100,000 customers affected in Tennessee, primarily in the Memphis and Nashville areas.

In Kentucky, rainfall from Katrina compounded flooding from a storm that had moved through during the previous weekend. A 10-year-old girl drowned in Hopkinsville. Dozens of businesses were closed and several families evacuated due to rising floodwaters. As a result of the flooding, Kentucky Governor Ernie Fletcher declared three counties disaster areas and a statewide state of emergency. Additionally, wind gusts up to 72 mph (116 km/h) resulted in some damage. Downed trees and power lines were reported in several counties in western Kentucky, especially Calloway and Christian counties. Overall, more than 10,000 utility customers in western Kentucky experienced power outages. The remnants of Katrina spawned a tornado in Virginia, damaging at least 13 homes in Marshall. In addition, approximately 4,000 people lost electricity. Over 3 in (76 mm) of rain fell in portions of West Virginia, causing localized flooding in several counties. At least 103 homes and 7 buildings suffered some degree of water damage. A number of roads and bridges were inundated or washed out. The remnants of Katrina produced locally heavy precipitation in northeast Ohio, ranging from about 2 to 4 in (51 to 102 mm). Numerous streams and rivers overflowed their banks, forcing the closure of several roads, including Interstate 90 in Cleveland. Two deaths occurred due to a flood-related automobile accident in Huron County. Additionally, hundreds of homes and businesses suffered flood damage.

Katrina spawned five tornadoes in Pennsylvania, though none resulted in significant damage. Up to 5 in (130 mm) of rain fell in western New York. Gusty winds also left approximately 4,500 people in Buffalo without electricity. The remnants of Katrina brought 3 to 6 in (76 to 152 mm) of rain to portions of Massachusetts, causing flash flooding in Bristol and Plymouth counties. Several roads were closed due to floodwater inundation in Acushnet, Dartmouth, New Bedford, and Wareham, including Route 18 in New Bedford. Very minimal impact was reported in Rhode Island, with winds downing a tree and two electrical poles in the city of Warwick. In Vermont, 2.5 in (64 mm) of rain in Chittenden County caused cars to hydroplane on Interstate 89, resulting in many automobile accidents. The storm brought 3 to 5 in (76 to 127 mm) of precipitation to isolated areas of Maine and up to 9 in (230 mm) near Patten. Several roads were inundated or washed out by overflowing brooks and streams, including sections of U.S. Route 1 and Maine routes 11 and 159. Several structures and one parked vehicle were also affected by the waters. Wind gusts up to 60 mph (97 km/h) also impacted parts of Maine, felling trees and causing power outages in Bar Harbor, Blue Hill, Dover-Foxcroft, Sedgwick Ridge, and Sorrento.

In Canada, the remnants of Katrina brought rainfall amounts in excess of 3.94 in (100 mm) to many locations between the Niagara Peninsula and the Saint Lawrence River valley. Severe local flooding occurred in Quebec, forcing the evacuations of dozens of homes in some communities as rivers began overflowing their banks and sewage systems were becoming overwhelmed by the influx of precipitation. Inundated and washed out roads, including Route 138 along the north shore of the Saint Lawrence River, Route 172 north of Tadoussac, and Route 385 near Forestville left several communities isolated for at least a week.

=== Economic effects ===

The economic effects of the storm reached high levels. The Bush administration sought $105 billion for repairs and reconstruction in the region, which did not account for damage to the economy caused by potential interruption of the oil supply, destruction of the Gulf Coast's highway infrastructure, and exports of commodities such as grain. Katrina damaged or destroyed 30 oil platforms and caused the closure of nine refineries; the total shut-in oil production from the Gulf of Mexico in the six-month period following Katrina was approximately 24% of the annual production and the shut-in gas production for the same period was about 18%. The forestry industry in Mississippi was also affected, as 1.3 million acres (5,300 km2) of forest lands were destroyed. The total loss to the forestry industry from Katrina was calculated to rise to about $5 billion. Furthermore, hundreds of thousands of local residents were left unemployed. Before the hurricane, the region supported approximately one million non-farm jobs, with 600,000 of them in New Orleans. It was estimated that the total economic impact in Louisiana and Mississippi may eventually exceed $150 billion. Forensic accountants were involved in the assessment of economic damages resulting from this catastrophe.

Katrina displaced over one million people from the central Gulf Coast to elsewhere across the United States, becoming the largest diaspora in the history of the United States. Houston, Texas, had an increase of 35,000 people; Mobile, Alabama, gained over 24,000; Baton Rouge, Louisiana, over 15,000; and Hammond, Louisiana, received over 10,000, nearly doubling its size. Chicago, Illinois received over 6,000 people, the most of any non-southern city. By late January 2006, about 200,000 people were once again living in New Orleans, less than half of the pre-storm population. By July 1, 2006, when new population estimates were calculated by the U.S. Census Bureau, the state of Louisiana showed a population decline of 219,563 or 4.87%. Additionally, some insurance companies have stopped insuring homeowners in the area because of the high costs from Hurricanes Katrina and Rita, or have raised homeowners' insurance premiums to cover their risk.