Two young men and a woman were killed and Maryland authorities were looking for two missing teenagers, as several days of torrential rains led to flooding in parts of the Mid-Atlantic region.

More than 2,200 people were evacuated from their homes in an area surrounding a Maryland lake that was approaching 25 feet above its normal level Wednesday, Montgomery County officials said.

In Virginia, more than 200 roads ware closed because of flooding, and the Virginia Department of Transportation expected that number to rise along with water levels.

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Crews were making emergency repairs, cleaning clogged drains and removing downed trees and limbs to keep roadways safe for motorists.

And in Washington, Mayor Anthony A. Williams declared an indefinite state of emergency because of the threat of power outages and other weather-related problems. The declaration allows the mayor to request assistance from the D.C. National Guard, which is under the command of president Bush. It also clears the way for the city to quickly acquire emergency supplies provide property owners with financial assistance.

The declaration is considered a first step toward seeking federal emergency disaster aid if necessary.

The mayor planned to spend Wednesday inspecting storm damage and visiting the crews making repairs.

The storm has claimed the lives of four people in Maryland since Monday, including a person killed in a single-car crash near Bowie that likely was weather related.

Police in Frederick County, Md. said three Myersville adults, between the ages of 19-29, were stranded in high water shortly before 9 p.m. Tuesday when Middle Creek, a stream that runs alongside Maryland Route 17, overflowed its banks and washed across the road, Frederick County Fire and Rescue Services spokesman Michael Dmuchowski said.

Neighbors pulled the three from their vehicle and got them loaded in the bed of a pickup truck. But the truck stalled in high water and the three were washed over the side.

Farmer David Grossnickle, who tried to rescue the three, said he saw them clinging to tree branches in the water screaming for help. Water from the creek stood about 5-feet deep on the road, Grossnickle said.

The last of the three bodies was recovered about 2 a.m. and sent to the medical examiner's office in Baltimore, said Jennifer Bailey, a sheriff's department spokeswoman. The sheriff's office identified the victims as Eric C. Zepp, 19, Jesse R. Haulsee, 24, and Angelia Haulsee, 29, all of Myersville.

In Montgomery county, officials ordered a mandatory evacuation overnight in the neighborhoods near Lake Needwood on the north side of Rockville after engineers observed soft and weakened spots on lake's earthen dam.

"These engineers and experts became increasingly concerned about the structural integrity of that dam," said Bruce Romer, chief administrative officer for Montgomery County. "As midnight approached, they began to observe actual seepage of water and leakage of water from the dam.

By 5:30 a.m. police and rescue crews had alerted residents of 500 apartment units and 700 homes and completed the evacuation, Romer said. About 100 people refused to leave their homes.

"The dam is failing in general, so that's why we're asking people to take what ever medications they need and leave," said Montgomery County Police Lt. Eric Burnett.

If the dam were to break it could lead to water levels up to 20 feet on several roads. A major thoroughfare such as Viers Mill Road could be under as much as 8 feet of water, county authorities said.

Residents were asked to leave the area and stay with family, friends or at a shelter established at Wheaton High School. About 150 people had gone to the shelter just before dawn.

The evacuees were generally confused about how long they would have to stay away from their homes.

"Someone just told me they are saying we could be here for three days," said Mehader Mekonne, who arrived at the shelter early Wednesday. "We don't have anywhere to go."

Sharon Forandbell, a resident of the Park Terrace apartment complex that was evacuated, said she was worried "that's she's not in a panic state."

A separate shelter for families with pets was set up at the Gaithersburg fairgrounds because the school does not allow pets.

Engineers were inspecting the dam Wednesday to determine what could be done to strengthen its walls.

Rescuers resumed their search early Wednesday for two teenagers who disappeared Tuesday evening near a rain-swollen creek between Frederick and Carroll counties.

The two youths, ages 14 and 16, who were reported missing by their parents after they failed to return home. They had gone to Little Pipe Creek near Route 194 in Keymar, 1st Sgt. Russell Newell, a Maryland State Police spokesman, said.

One bicycle and clothing were found near the creek, which runs from Frederick County to Taneytown in Carroll County, Newell said.

Other jurisdictions reported little trouble.

"The forecast is much more favorable," Maryland State Highway Administration David Buck said. "I'd say we're 99 percent past the worst of it in terms of road closures and flooding."