MONTGOMERY, Ala. (Reuters)—Insured losses from last week's devastating tornadoes in Alabama are expected to exceed the $2 billion in losses inflicted on the state by Hurricane Ivan in 2004, a state official said Wednesday.

"This is the worst disaster dollar-wise. Ivan was a lot different but this is more difficult," Alabama Insurance Commissioner Jim Ridling said at a news conference after meeting executives from leading insurance companies who are assessing the damage to the state.

Alabama and six other Southern states are counting the cost of the United States' second-deadliest tornado outbreak on record. It destroyed whole neighborhoods and killed more than 330 people, more than 230 of them in Alabama alone.

Mr. Ridling said Alabama would bear the majority of the overall $2 billion to $5 billion insured losses estimated for all of the affected states by one disaster risk modeler, EQECAT, last week.

"In all my years in the insurance industry I have never seen anything so violent and widespread," he said, adding some 17,000 insurance claims adjusters had been given badges so far to work in the state following the tornado disaster.

Both Mr. Ridling and Alabama Gov. Robert Bentley were reluctant to give a more precise figure for the state's insured losses, saying evaluation of the damage, as well as overall fatalities figure, was continuing.

"We don't know yet the amount of houses (destroyed) or the monetary value," Gov. Bentley said. "We're trying to assess that now."

EQECAT had cited reports of nearly 10,000 buildings destroyed.

President Barack Obama, who last week visited the wrecked Alabama college city of Tuscaloosa, has promised full federal support to help the storm-battered South recover from the worst U.S. natural disaster since Hurricane Katrina in 2005.

Katrina caused $1 billion in insured losses to Alabama, while Ivan the previous year had inflicted $2 billion in losses, state insurance officials said.

President Obama has signed major disaster declarations for Alabama, Mississippi and Georgia.

The death toll from last week's swarm of tornadoes was the second-highest inflicted by tornadoes in U.S. history. In 1925, 747 people were killed after twisters hit the U.S. Midwestern states of Missouri, Illinois and Indiana.