According to a U.S. Congressional Budget Office (CBO) estimate of 6 Sept, the insured cost of Hurricane Katrina could exceed $30 billion. According to Swiss Re on 12 Sept., the insured cost is probably actually $40 billion. That makes Katrina the most costly disaster ever for insurers, higher than the $35 billion for Hurricane Andrew in 1992,
$32.5 billion for 9/11, or $15-$20 billion for the 1994 Northridge Earthquake in Los Angeles.