Witt has been monitoring and assessing storm damage with the help of state and local emergency managers, he tells CBS 'This Morning' Co-Anchor Mark McEwen.
Says Witt, "I think you can see the difference in Wilmington from Hurricane Fran and what they have done in preventionÂ… You can see they are building better, taking the prevention measures and putting them in place.
"I think it's very clear [that] with Bonnie, you're not going to have as much damage [as with Fran], but still it will be quite a bit," he adds.
FEMA has spent $20 billion in the past 10 years to help people repair and rebuild their communities after natural disasters.
Witt also said FEMA will be setting up an 800 number to allow hurricane victims to apply for aid by phone.