State and city officials were scrambling Saturday to determine the extent of damage caused by a tornado that touched down late Friday. The storm uprooted trees, smashed windows and peeled back roofs throughout downtown and in nearby neighborhoods such as Cabbagetown, Vine City and East Atlanta.

The damage is expected to be significantly more than $150 million, according to a preliminary estimate by State Insurance Commissioner John Oxendine. Most of that estimate is based on damage to the Georgia World Congress Center, where windows were shattered, seats were scattered and portions of the ceiling sustained major damage.

"There is not a building that is safe" at the Congress Center, Oxendine said.

Glenn Allen, a spokesman for Oxendine, said Saturday afternoon that the initial damage assessment is likely to increase as officials get more information about the damage beyond the downtown area. In Polk County, for example, close to 40 homes may have been hit badly by the weekend's storms.

Atlanta Mayor Shirley Franklin said work crews had been out on the streets since 1 a.m. Saturday. She said the city has received help from Fulton and DeKalb counties and the state in initial clean-up efforts. Throughout the day, work crews were out removing debris and clearing fallen trees and limbs from streets and parks.

"We are moving in textbook fashion to make sure that both state and federal government officials are engaged in what we are doing," Franklin said.

City officials also dispatched a preliminary damage assessment team consisting of building and zoning officials, fire-safety personnel and others to collect information about damage to private and public property throughout the day.

Rocky Moore, director of the Atlanta-Fulton County Emergency Management Agency, said that officials were assessing the city's buildings and noting problems ranging from broken windows to major internal structural damage.

In several neighborhoods, business leaders and homeowners were trying to determine the damage to their property. John Heid, a spokesman for Allstate Insurance, said Saturday that it was too early to know the financial impact of the damages to private property owners. He said adjusters were on the ground taking claims, and that customers from Alabama to Georgia had suffered damage from the storms.

Many homeowners also were dealing with damaged trees. Greg Levine, program director of Trees Atlanta, said it is important for homeowners who have fallen trees or limbs on their property to call a professional, insured tree-removal service.

"Often you'll have more people injured after storms," Levine said. "If you make it through a storm, don't do work that you're not prepared to do. Leave it to professionals."

Levine also suggested that homeowners hire a certified arborist to inspect trees on their property for problems before deciding to cut them down in the aftermath of this weekend's storms. He said some possible signs of a tree in distress are exposed roots, major cracks in the trunk and a dramatic shift in angle.

Staff writer Eric Stirgus contributed to this report.