The counties include the hardest-hit by Irma: Miami-Dade, Broward, Monroe and Collier.
Irma also killed at least another 40 people in the Caribbean before hitting the Keys September 10 as a Category Four hurricane with winds of 180 miles (295 kilometers) per hour, and then barreling up the length of the state.
He said the state's damages could exceed claims in Texas generated by Hurricane Harvey, which total $11 billion so far, mainly because of Irma's flooding of expensive waterfront properties in Florida.
Implying debris is hindering the restoration of electricity and other relief efforts, Gov. Rick Scott set a noon Tuesday deadline for Florida counties impacted by Hurricane Irma to submit detailed debris-removal plans.
Security First Insurance, the second largest insurer of single-family homes in Florida, with 340,000 overall policies, is one of the companies that has expanded since the last major hurricane seasons. It had given Palm Beach County residents the estimate of Sunday evening.
"We've got a lot of work to do", Burt said. "And our job is to try to put people's lives back together as fast as we can".
So far, he said, FEMA has received 142,000 claims of this nature and distributed $153 million in Florida.
Hermine made landfall south of Tallahassee and caused damage across parts of North Florida.
In Florida, 1.7 million households have federal flood insurance, by far the most of any state in the country.
Other members of the team, which included specialists in meteorology, storm surge, hydrology, engineering, finance, computer science and statistics, were from the University of Florida, Florida State University, the Florida Institute of Technology, the University of Miami and the National Oceanic and Atmospheric Administration. The official figures are compiled by the Florida Department of Law Enforcement and the Division of Emergency Management based on reports by county medical examiners.
