Pedestrians try to escape an approaching storm Tuesday along M Street in Georgetown. (ASTRID RIECKEN/For The Washington Post)

Fallen trees stopped or slowed trains and cars Tuesday evening and were blamed for a motorists’s death, while lightning ignited fires and more than 100,000 homes and businesses lost power as fierce thunderstorms rolled across the region.

The death came in the Poolesville area of Montgomery County. A car struck a fallen tree at Darnestown and Cattail roads, bringing electrical wires down onto the vehicle, according to police and fire spokesmen.

Early Wednesday morning police said the victim was a 79-year-old man who was driving a pickup truck. The police account said nothing about the electrical wires.

At least two apartment houses were set on fire by lightning strikes, one in Arlington on North 21st Road and the other on Lakeside Drive in Greenbelt, Md.

As winds rose, skies darkened and rain poured down, authorities reported fallen trees throughout the region. In Montgomery alone, trees fell on houses in three places. Damage resulting from falling trees was also reported in Fairfax County.

An apartment house in Greenbelt, Md. was one of two in the DMV-area set on fire by lightning during thunderstorms in the region June 23. A resident said he lost "everything" in the blaze. (WUSA9)

All forms of transportation felt the storm’s effects: cars, planes and trains. According to various accounts, fallen trees and electrical problems impeded rail service south of Philadelphia.

Amtrak service was suspended for about two hours, and Maryland’s MARC commuter trains were delayed.

MARC ascribed delays to electrical difficulties that caused signal problems in the Aberdeen, Md., area.

A Virginia Railway Express train was delayed near Rolling Road in Fairfax County after a tree fell, blocking the tracks.

At one point, BGE reported about 48,000 homes and businesses without electricity in its service area. Dominion Virginia Power put the number of outages at about 40,000 in the Northern Virginia area. Thousands more residents of the region in areas served by Pepco, and Potomac Edison also saw the lights go dark for a time.

More than an inch of rain fell at Baltimore-Washington International Marshall Airport between 6 p.m. and 7 p.m. More than four-fifths of an inch fell at Reagan National Airport.

Numerous trees fell in northern Montgomery, some on thoroughfares, said Pete Piringer, spokesman for the county fire and rescue service.

Washington Nationals shortstop Danny Espinosa watches the storm clouds during a rain delay Tuesday. (Jonathan Newton/The Washington Post)

Houses were struck by falling trees in at least two spots in the Germantown area of Montgomery, Piringer said, one on Climbing Ivy Court and the other in the 20200 block of Waterside Drive.

Structural damage resulting from falling trees was also reported in Fairfax County,where a report to the National Weather Service said several trees struck homes in the Burke and West Springfield areas. In Northern Virginia, a fallen tree near Route 123 shut the southbound lanes of the George Washington Parkway for hours.

Many trees fell in the Sudley area of Prince William County, Va.

Thunderstorms with 30 mph wind gusts were reported about 6 p.m. in the Leesburg area of Virginia’s Loudoun County.

An hour later, squalls and wind were reported at Reagan National Airport, with a 48 mph gust.

The Weather Service issued a severe thunderstorm warning around 6 p.m. for parts of the District and surrounding counties; it said the storms were capable of producing 70 mph winds. By 7:30 p.m. Washington was deluged with rain, as thunder pealed and lightning flashed across the gray evening skies.

During the storms, hail fell in many places, and was compared in size to a variety of circular or spherical objects. These included peas, dimes and quarters.

Hailstones were also likened to pingpong balls. Hailstoes of such size broke windows on cars and in houses in the Cockeysville area of Baltimore County, the weather service was told.

The Weather Service received a photograph from the Cockeysville area showing a hefty hailstone composed of many smaller stones frozen together, like a clump of marbles. It rested in the palm of someone’s hand, glistening.

The storms arrived, as many summer storms do, near the end of a steamy afternoon, which saw the mercury reach 96 degrees in Washington.

Before the heaviest rain arrived in the District, the Washington Nationals said their game with the Atlanta Braves would be delayed “by impending weather.” It eventually got underway and continued late into the night.

Although miles apart, both members of a Virginia couple felt the storm’s effects.

Stephen Mandolesi, who was heading home from New York, said his Amtrak train was experiencing long delays. He said his train was held in Philadelphia for a half hour.

“Now we’re are 7 trains behind trying to get into Delaware,” he said in an e mail.

But at their home in Burke, his wife faced her own inconveniences. The storm had cut off power, Mandolesi he said.

For all its deadly and destructive effects, the storm moved relatively swiftly across the region. Though severe in its effects, the line of storms had moved on from many parts of the Washington area before nightfall.

As they were illuminated by the setting sun, some of the last clouds to scud across the sky seemed to have a silver lining.

And in some places, the departing clouds reflected the day’s last golden rays of sunshine.