With rain falling again, cleanup crews were busy Tuesday piling sandbags and pumping water from the basement of the Internal Revenue Service building and from steam tunnels under the city after days of heavy rain flooded the capital.

In Maryland, dozens of residents were evacuated from homes in Laurel, Bowie and Maryland City because the flood gates were opened at a dam on the Patuxent River.

The Potomac River — which runs through Washington — was also rising and expected to approach flood stage on Thursday but not pass it, the National Weather Service said.

The more than 7 inches of rain fell on the nation's capital in a 24-hour period Sunday and Monday, shutting down several federal buildings and closing some of the city's busiest tourist attractions just days before the Fourth of July weekend, and forecasters warned that more rain was likely every day this week.

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The National Archives and IRS headquarters were among several buildings still closed Tuesday because of flooding or storm-related problems.

None of the flooded buildings had structural damage, but water in the basements damaged air-conditioning, electric wires and others building systems, said Mike McGill, a spokesman for the General Services Administration, which manages federal buildings.

"We're still in the process of evaluating the damage to those systems," he said.

Officials at the Justice Department, which handles day-to-day operations it its headquarters, said it could take a week to clean up the mess there an repoen the building.

Commuters and tourists, meanwhile, slogged through the muddy aftermath of the storm, trying to avoid washed-out roads.

With the continuing threat of flash flooding, government employees were given the option of taking a personal day, though the Office of Personnel Management said the federal government was operating.

Much of the eastern seaboard remained under the threat of rain and flooding Tuesday and through much of the week because of a low-pressure system stalled along the coast.

"Areas that have been hard hit could see another round of flash flooding," said Steve Rogowski, a meteorologist with the National Weather Service office in Sterling, Va.

The National Hurricane Center was also tracking a stormy area about 140 miles south of Cape Fear, N.C., that it said could develop into a tropical depression at any time Tuesday. Flood watches and warnings were in effect for the most of North Carolina and other counties as far north as upstate New York.

In Washington, some downtown streets remained closed as water from flooded building basements was being pumped into the sewers.

The National Archives — where the Declaration of Independence and Constitution are kept secure under glass — was shut down because the moat surrounding the building on Pennsylvania Avenue had flooded, spokeswoman Susan Cooper said. She said all records and national treasures were "safe and dry."

For tourists Sonja Hawn and her two young children, of Laurinsburg, N.C., the rain made for a damp 20-minute walk to the National Museum of American History. When they arrived, they found it closed by the weather — but took it in stride.

"We're going to make the best of it," Hawn said, adding they would try to visit the National Museum of the American Indian instead.

The tree that fell near President Bush's front door was also historic — White House officials said it was at least 100 years old. Bureau of Printing and Engraving could not immediately confirm reports that it was one of the trees depicted on the back of the $20 bill.

Outside the capital, as much as 14 inches was reported in parts of Delaware and 12 inches at Federalsburg, Md., on the Eastern Shore.

In Elkton, Md., a 6-foot wide, 2-foot deep hole opened on I-95, blocking traffic in two northbound lanes, state police said. The Potomac River's Northwest Branch flooded U.S. 29, a major commuter route through Silver Spring, Md., with 5 feet of water and left a layer of mud. Most flooded roads had reopened by late Monday night.

More than 10 inches of rain fell on Hyattsville, Md., where firefighters used boats to rescue 69 people trapped in flooded homes, said Mark Brady, a Prince George's County fire and rescue spokesman. Boats also were used to rescue 30 people marooned in Chevy Chase, Md., and officials were preparing for the possibility of more water rescues Tuesday.

"It's going to be a challenging week," said Maryland State Highway Administration spokesman David Buck.

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