The front-seat passenger, Cherise Mayes, 27, of Martinsburg, W.Va., was taken to Martinsburg City Hospital, where she was in satisfactory condition Saturday night.
No one in the car was wearing seat belts, Plumer said.
Police were not sure why the accident happened. They know that Mason's northbound car went off the right side of the road. She overcorrected and sent the car into a tree off the left side of the road. The car overturned and hit another tree, trapping Mason and Powell inside for a time, Plumer said.
Earlier Saturday morning, at 2:19, an unidentified man was hit by a 1994 Toyota pickup truck in front of Alibi's Club on U.S. 11, police said.
The driver of the truck, Dale Jackson, 44, of Martinsburg, W.Va., was southbound. She didn't see the man wearing dark clothing until just before her truck struck him, Plumer said.
Jackson won't be charged, police said.
The man was taken by ambulance to Martinsburg City Hospital and then flown to Fairfax Hospital, where he was in stable condition Saturday night.
A third accident occurred on the same highway near Marlowe, W.Va., at about 2:30 a.m., police said.
Jacob Hunt, 44, of Baltimore, was southbound when his 1980 Honda hatchback left the right side of the road. Like Mason, he overcorrected and went off the left side of the road, police said.
Hunt's car hit an embankment and overturned. The car slid 50 to 60 feet on its top before coming to rest, police said.
Hunt was taken to Martinsburg City Hospital and later flown to Fairfax Hospital. His condition was serious Saturday night.