Hurricane Katrina
Updated: 25 January 2007
Profile
|
Event dates |
24 August - 03 September 2005 |
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Affected areas |
Bahamas, US, North Atlantic, Florida, Gulf of Mexico, Louisiana, Mississippi, Alabama, Tennessee |
|
Fatalities |
= 1836 (September 2007) |
|
Homeless |
> 75 000 (23 December 2005) |
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Insured loss |
USD 66 000 000 000 (including flood losses) |
|
Economic loss |
USD 125 000 000 000 |
Event description
Hurricane Katrina formed as a tropical storm in the southern Bahamas and strengthened over the central Bahamas on its way to making landfall in Florida on the evening of 25 August. Katrina came ashore along the Miami-Dade and Broward county line between Hallandale Beach and North Miami Beach as a Category 1 hurricane with winds of 129 km/h (80 mph). The hurricane moved west towards the Gulf of Mexico, spending less time over Florida than anticipated, but led to 11 fatalities, flooding and left millions without power.
( c) NOAA
Hurricane Katrina was reduced to a tropical storm while still over the Everglades but quickly reached hurricane strength again as it moved into the Gulf of Mexico. With water temperatures of around 27° C (80° F), unstable atmospheric conditions, moist air and little to no wind shear in the Gulf of Mexico, conditions were perfect for Katrina to rapidly strengthen, reaching Category 5 status with winds exceeding 250 km/h (155 mph) as it sped towards New Orleans for its second US landfall.
For the first time in its history, New Orleans was placed under mandatory evacuation given the high flooding probabilitiy since many parts of the city are some 3 metres below sea level and storm surges between 4 - 5 m (13 - 18 ft) were expected. On 29 August, Katrina hit Grand Isle, Louisiana, about 110 km (70 miles) southeast of New Orleans, as a strong Category 4 hurricane moving at about 24 km/h (15 mph) with winds approaching 240 km/h (150 mph).
Katrina moved slightly east of New Orleans before turning north into Mississippi. This reduced flood risk due to storm surge. However, a Lake Pontchartrain levee was breached, leading to rapid flooding of downtown New Orleans. About 80% of the city has been flooded. Together with the flooding, contamination and pollution from chemicals and refuse will make cleanup very difficult and costly.
In Biloxi, Mississippi, Katrina was responsible for at least 30 casualities due to drowning and the collapse of an apartment complex. In Gulfport, storm surge waves of up to 7 metres flooded the coastal city causing widespread damage. Alabama was also severely hit by wind and flooding and Mobile, in particular, was severely flooded.
As Katrina tracked through northern Mississippi into Tennesee, it was downgraded to a tropical storm, but still generated heavy rainfall.
Hurricane Katrina caused the following:
- extensive wind-related property damage
- extensive flooding along its path - the NFIP (National Flood Insurance Program) covers residential and small commercial risks
- flooding and pollution in New Orleans
- oil rig damage in the Gulf of Mexico, where 3 rigs have reportedly broken free from their moorings. The Royal Dutch Shell Mars platform, producing as much as 15% of the Gulf output, has been damaged. The damage extent is still unknown.
- damage to oil refineries along the coastal areas
- power line damage resulting in extended power outages
Insured loss
Published industry estimates for the Florida and Louisiana landfalls (as per 19 September) are as follows:
|
AIR |
USD 17 bn - 25 bn |
|
EQECAT |
USD 14 bn - 22 bn |
|
Insurance Information |
USD 10 bn - 15 bn |
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Institute (III) |
|
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RMS |
USD 40 - 60 bn |
Swiss Re’s share of the loss
Based on current estimates, Swiss Re expects its Katrina-related claims to be in the range of USD 1.2 bn before tax.
Hurricane Katrina storm track
Source: Swiss Re
