Last update: 3:20 p.m.
A powerful storm with wind gusts up to 60 mph struck a brief but hard blow on Montgomery and Prince George's counties Friday night, leaving hundreds of thousands without power in a potentially dangerous heat wave.
One person was killed in Montgomery County, according to police.
Residents hunkered down against the wind, flashes of lightning and driving rain as the National Weather Service issued severe storm warnings. Large swaths of Montgomery County and Prince George's County lost power in what meteorologists have identified as a derecho.
As of 3:00 p.m. Saturday, some 224,540 customers (73 percent) in Montgomery County and 130,183 customers (58 percent) in Prince George's County were without service, according to Pepco.
Officials also said about 500 out of 800 traffic signals in Montgomery County were dark as of Saturday morning.
The Washington Suburban Sanitary Commission issued mandatory water restrictions for all Montgomery and Prince George’s County customers after the storms reportedly knocked out power to WSSC’s two water filtration plants.
The body 71-year-old woman was discovered Saturday morning when fire and rescue personnel responded to a call for a downed tree in the 10000 block of Grant Avenue in Silver Spring. She was apparently killed when a large Maple tree fell through the roof and onto her bed.
Meanwhile, a tree that fell across Brookville Road near Thornapple Street in Section 3 of the Village of Chevy Chase didn't fall onto any houses, but it was still frightening enough that "everyone thought they were going to die," according to resident Edward Ponzi.
A drive around the Kensington and Bethesda areas proved hazardous before dawn, with major roads, including Connecticut Avenue, blocked by downed trees. Traffic lights at major intersections, including East-West Highway, were dark, and roads were littered with debris.
Police and work crews were out setting up roadblocks for downed trees and conducting cleanup.
Part of the roof of Park Tanglewood apartments, a seven-story building in Riverdale Park, was torn off by the high winds, displacing hundreds of residents.
The Washington Post reported that, in all, more than 1.5 million homes and businesses across Maryland and Virginia lost power. A Pepco spokeswoman said some customers could be without service for multiple days.
Highs on Saturday were around 100°, with more storms expected between 4 and 8 p.m.
"It's pretty brutal with no AC in this kind of heat," Greenbelt resident Fred Wilcox told Patch Saturday afternoon. "…It could really be life threatening for other people."
Cooling centers have been opened in both and counties, while many pools in Prince George's will be holding extended hours and waiving admission fees on Saturday.
To report power outages, call Pepco at 877-737-2662.
This story was updated at 6:50 p.m. with additional quotes.
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