Original: Total damages have been estimated at $81.2 billion, and at least 1,836 people were killed by the storm; Katrina is the costliest hurricane in U.S. history, surpassing 1992's Hurricane Andrew, and the deadliest hurricane in the U.S. since 1928.
Simplified: It beat the old record from Hurricane Andrew. Katrina left $81.2 billion in damage and 1,836 deaths.