CHARLESTON, S.C. - Even as tree limbs were cleared away and power gradually came back on across eastern South Carolina after Tropical Storm Gaston, officials turned a wary eye Monday to Hurricane Frances.

"I hope it's not the way we spend our Labor Day," Gov. Mark Sanford said during a meeting with area mayors to discuss the damage wrought by Gaston after it hit the coast northeast of Charleston on Sunday.

Sanford urged coastal residents to monitor Frances with its 120 mph winds that was well at sea and days away from the Southeast coast.

While Gaston caused flooding, and left people with trees down and power out "it's not the kind of catastrophic damage we see in a major hurricane," the governor said.

He said he worries that, after several such storms affecting the state this year "people will say it's not that bad. A Category 4 or Category 5 storm would be very, very bad and it's important we not grow complacent."

Any evacuation would be huge because of the size of Frances, warned Charleston Mayor Joseph P. Riley Jr.

"The whole state would be naked," he said. "This will be a challenge to all of us because we have so many more people living down here now. We really haven't had a ... potential challenge like this."

Gaston, which came ashore with winds of 70 mph - just under hurricane strength - brought rains estimated at 13 inches in places.

The storm flooded homes, toppled trees in soil already saturated by Hurricane Charley earlier this month and cut power to 172,000 electric customers.

Schools in Charleston and Berkeley County were closed Monday because of power problems, as was one high school in Dorchester County.

Sanford flew over eastern parts of the state Monday morning to get a glimpse of the damage.

Early reports indicated Gaston had done as much damage in South Carolina as Hurricane Floyd in 1999. That storm, which hit the northeastern part of the state, caused about $53 million damage.

But after his flight, Sanford noted that floodwater in some areas has receded and damages may not be that high. A final figure, he said, would have to wait until counties complete their damage assessments.

As of 4 p.m. Monday, the South Carolina Insurance News Service said about 2,600 insurance claims had been filed totaling about $5.2 million as a result of Gaston. Most of the claims were coming from Mount Pleasant, Isle of Palms and North Charleston in the Lowcountry.

By Monday evening, fewer than 29,000 customers remained without power in the Lowcountry and the Pee Dee, where the storm tracked after making landfall.

While the work of recovering from Gaston continued, state emergency officials stepped up their monitoring of Frances and were in regular contact with the National Hurricane Center.

"The track has turned a little more toward South Carolina unfortunately," Ron Osborne, director of the state Emergency Management Division, told the mayors.

"The good news is that now the intensity has gone down from 140 mph to 120 mph. But it still has yet plenty of time to intensify," he said.

Osborne said the National Guard could be placed on standby as early as Tuesday to be ready to help with evacuations and provide security if the storm threatens.

Evacuations could be needed by week's end if the storm approaches, he said.

"This particular storm is strong, big and we really need to monitor it closely," Osborne said. "We're looking toward the end of the week if it stays on this track to take some action."

While the damage from Gaston was scattered widely, in some places, it was severe.

Berkeley County supervisor Jim Rozier said the communities of Bonneau and St. Stephen were hard hit by the storm and received as estimated 13 inches of rain in 2 1/2 hours.

"It just seemed to rain forever," he said. Ten houses in St. Stephen were completely flooded and more than two dozen people had to be rescued from the Short Stay community because of rising waters.

A "fair amount" of street flooding was reported around Florence and Lake City, said Dusty Owens, emergency management director for Florence County where officials monitored rising waters on Black Creek on Monday.

Florence received about 7 inches of rain during the storm, which also knocked down billboards and storage buildings and toppled trees.

Roland Windham, the Charleston County administrator, told Sanford a big problem after Charley and Gaston will be mosquitoes.

He asked Sanford to help the county seek reimbursement from the U.S. Army Corps of Engineers for spraying for mosquitoes in spoils areas used to put silt dredged from rivers and Charleston Harbor.