With an estimated cost of $148.8 billion, Hurricane Katrina is far and away the most expensive natural disaster in modern U.S. history. Based on damage estimates that have been adjusted for inflation, this estimated cost is viewed in 2013 dollars. Hurricane Katrina had its greatest impact on Alabama, Florida, Louisiana and Mississippi.

More than one million people in the Gulf region were displaced by Katrina. At their peak, hurricane relief shelters housed 273,000 people. Later, approximately 114,000 households were housed in FEMA (Federal Emergency Management Agency) trailers. It cost FEMA at least 25 billion to help with housing relief efforts.

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