A pair of volatile storms pelted the Washington region with enough rain to trigger flash flooding in dozens of places Friday, but they spared the area from tornado devastation that forecasters had feared.

A tornado did no damage when it touched down inside the perimeter of Baltimore-Washington International Marshall Airport at 7:19 p.m. There also were reports of severe wind damage in two places north of Baltimore — Fallston and Finksburg — but it was unclear whether it was caused by tornadoes.

Closer to Washington, there were several tornado warnings but there was no evidence that fallen trees, downed power lines and other wind damage were the work of a true twister.

The first storm arrived just as schools were letting out and evening rush hour neared, turning the exodus toward home and weekend destinations into a mass of stalled traffic.

Bursts of hail and rain that fell fast and hard slowed drivers and blocked many of them as dips in secondary roads filled with water.

Some schools delayed the departure of buses carrying children home, and flights were grounded briefly at the region’s three major airports, causing a domino effect that delayed passengers during one of the busiest times of the day.

In one of the most dramatic incidents arising from the storms, three teenagers were rescued from the Northwest Branch of the Anacostia River in Mount Rainier, said Mark Brady, a Prince George’s County fire department spokesman.

He said they were washed in from the banks about 7:15 p.m. and could not return to shore. But he said they managed to grasp the supports of the 38th Street bridge until firefighters arrived to rescue them.

“This was a life-or-death situation,” Brady said. “This incident could have very easily turned out to be tragic.”

He said firefighters used ropes, pulleys and a safety harness to pull the three to safety over about 45 minutes.

Brady said they were taken to Children’s National Medical Center with what were described as hypothermic symptoms. They were reported in good condition late Friday.

Baltimore Gas and Electric said 7,059 customers were without lights in Howard County. Dominion Power was reporting 390 customers without power in Northern Virginia at 9:15 p.m.; Pepco reported 5,233 without power in the District and about 500 in Prince George’s.

The lights went out in Union Station, and a downed tree on Metro’s Orange Line delayed trains near Cheverly. Metro officials where thwarted by flooded streets when they sought to send buses to rescue stranded passengers.

The Nationals postponed their home game with the Atlanta Braves, announcing that scheduled starting pitcher Stephen Strasburg would start instead on Saturday.

Tornado warnings were issued repeatedly as the evening began.

The famed Tornado Alley in the nation’s heartland has earned its reputation, but the Washington region is no stranger to twisters. The strongest tornado on record in Maryland, with winds estimated at 207-260 mph, flattened La Plata and parts of two surrounding counties 10 years ago. Five people died, 120 were injured and property damage was estimated at more than $100 million.

That tornado came seven months after one that killed two students at the University of Maryland in College Park. It tore off roofs and toppled a church steeple as it churned toward Laurel.

A 1973 tornado in Northern Virginia damaged or destroyed almost 300 homes and ripped the roof off Woodson High School. There were 37 injuries reported but no deaths.

The region’s most deadly tornado hit a school in La Plata in 1926. It lifted a school, and the 60 students and two teachers inside, blowing it 50 feet into a grove of trees. Thirteen students died, and the tornado killed three other people before it ended.