Soledad Espino was fixing dinner while her husband picked up their children from karate class Thursday when muddy water seeped onto the floor of their mobile home off Route 1 in Woodbridge.

In minutes, it was lapping at her knees. A friend was pounding on her door, telling her to get out. And then a brown torrent swept over the Holly Acres Mobile Home Park, destroying her home and leaving Espino with little more than the clothing she had hastily stuffed into a tote bag.

“I wanted to save more, but we didn’t have time,” Espino said Friday. “It happened so fast. We [lived] 12 years in this trailer, and it’s all gone.”

The damage to the trailer park was so severe that Prince William County officials condemned every single home Friday, leaving about 100 people homeless.

Washington — a region that has been baked by heat, shaken by an earthquake, soaked by a hurricane and set on edge by a new threat of terrorism in recent weeks — awoke Friday to a new mess after Thursday’s flooding.

A day of relentless rain Thursday built into sneaky, swift-rising rapids that swept four people to their deaths, including a 12-year-old boy, forced hundreds to evacuate in Fairfax County, and shut several major highways, including the Capital Beltway and Interstate 66. At the peak of the rains, dozens of drivers had to be plucked by rescuers from their vehicles.

Some Fairfax County schools became impromptu shelters for hundreds of students stranded by the storm after their buses encountered traffic jams and impassable roads. In Prince William, about 300 people took shelter at Woodbridge High School, many from Holly Acres.

By Friday, officials were working to clear debris and tally damages to washed-out bridges and roads, commuters began returning to the formerly flooded Reston North Park and Ride to claim their mud-caked vehicles, and hundreds of people evacuated from the Huntington area returned after county inspectors examined their homes along Cameron Run to ensure their safety.

The effects of the deluge still are being felt this weekend, as high school football games in Northern Virginia and Prince George’s County, other outdoor sporting events and even some 9/11 commemorations have to be moved or rescheduled.

A joint search Friday by Fairfax County and military personnel from Fort Belvoir recovered the body of a fourth victim who had been missing since Thursday night. The Virginia Railway Express halted rail service Friday, and Fairfax County public schools canceled classes and warned that damage could disrupt bus routes next week.

Gov. Robert F. McDonnell (R) declared a state of emergency, while Sen. Sen. Mark Warner (D) toured Huntington, balancing the promise of a swift federal response while trying not to create unrealistic expectations at a time of severe budget problems.

Some Huntington residents, mindful of floods that washed into their homes three times in the past five years, expressed bitterness about promised remedies that have never come.

“They’re going to give us free pizza, free cleaning supplies, loans but not really assistance,” said Geoff Livingston, who evacuated his house about 6:20 p.m. Thursday and later posted video of the flood on his blog.

Maryland also took a hit. In Upper Marlboro, workers mopped up at the Prince George’s County Administration Building, which had taken on as much as two feet of water Thursday.

Keith Nechanicky, general manager of Certified Building Services, said crews found frogs and bluegills flopping around the ground floor of the six-story building and returned some of them to the pond next door. County officials said they were still assessing the cost of damages. Several roads, though no major arteries, remained closed.

But Northern Virginia appeared to have taken the brunt of the flooding caused by the stubborn remnants of Tropical Storm Lee.

Fairfax County Board of Supervisors Chairman Sharon Bulova (D) said Friday that early estimates by the Virginia Department of Transportation suggest that the county’s transportation network, including damaged roads and bridges, sustained $6 million to $10 million in damage.

In Huntington, streets filled with neighbors Friday who were busy sweeping, pumping and spraying ankle-deep sludge away from their homes. A small plow was needed to clear the muck that Cameron Run deposited on Fenwick Street.

Brothers Timothy and Titus Boyd said nearly six feet of water poured into their basement on Arlington Terrace, a rerun of a flood in June 2006. Several residents said the force of the water in the basement was so strong that it toppled their washers and dryers, and one deep freezer was turned upside down.

Several marveled at how quickly the water came up.

“I’m 6-2, I evacuated with my 15-month-old daughter on my shoulders, and the water came up to here on me,” said Stacy Hoeflich, indicating her chest.

Early Friday, the Fairfax County Department of Public Works and Environmental Services inspected about 100 houses in Huntington to ensure their safety before evacuees could return. Some of the houses received yellow tags that required homeowners to have contractors examine or repair electrical, plumbing or structural damage. None was red-tagged, forbidding residents from returning. County officials plan to hold a meeting Saturday at Whitman Middle School for Huntington residents affected by the flooding.

Supervisor Gerald W. Hyland (D-Mount Vernon), who represents Huntington, said the flooding also restarted discussions about whether the county should explore a way of buying out residents who live in flood-prone areas.

“Some have suggested that that’s a solution, to buy out all of those homes and relocate those people, instead of spending millions of dollars to put up a flood wall,” Hyland said.

The U.S. Army Corps of Engineers, in an April 2009 report, estimated the cost of building a levee against flood protection to be more than $20 million — a price too high to be cost-effective, the agency said.

Staff writers Mark Berman, Emma Brown, Tim Craig, Kafia Hosh, Tom Jackman, Anita Kumar, Ben Pershing, Miranda S. Spivack and Nikita Stewart contributed to this report.