Hurricane
Katrina began as a very low pressure weather system, which
strengthened to become a tropical storm and eventually a hurricane
as it moved west and neared the Florida coast on the evening of 25
August.
Animated
guide: How Hurricanes form
After crossing southern Florida - where it left some 100,000
homes without power - it strengthened further before veering inland
towards Louisiana, eventually making landfall at Grand Isle,
approximately 90km south of New Orleans, at 10am local time on 29
August.
At this point, Katrina's sustained wind speed was approximately
200 km/h. The storm passed directly through New Orleans, destroying
many lighter buildings and causing extensive damage to others.
Hurricane force winds were recorded along an 200km stretch of
coastline, with scenes of similar destruction and flooding in
Louisiana, Mississippi and Alabama. Storm surges from the sea caused
flooding several kilometres inland in some places.
Hurricane Katrina hits