Four people died in traffic accidents in Montgomery and Fairfax counties early yesterday.

A Gaithersburg man was killed around 3:20 a.m. when the car he was riding in struck a telephone pole near Rte. 355 and College Parkway, Montgomery County police said. Tomas Bermudez Jr., 36, of 350 Summit Ave. was pinned inside the 1981 Chevrolet Chevette, authorities said. Two other passengers in the car, driven by Francisco Fonseco, 30, of Rockville, were taken to Shady Grove Adventist Hospital, police said. Officials were investigating the cause of the accident.

A Rockville man walking along the westbound lane of Montgomery Village Avenue near Duffer Way was struck by a car about 1 a.m., police said. David Hatfield, 18, of 13923 Travilah Rd. was pronounced dead at Shady Grove Adventist Hospital, officials said. No charge had been filed, police said.

In Virginia, a 17-year-old girl from Great Falls was killed about 12:45 a.m. in Reston when the car she was riding in flipped over on Fox Mill Road near Pinecrest Road, Fairfax County police said. Michelle Turner died of massive head injuries at Fairfax Hospital, police said. The driver of the car, a 16-year-old girl, was treated at a hospital in Reston and released, police said. The cause of the accident was under investigation.

And a 17-year-old youth from Dunn Loring was killed about 2 a.m. near Vienna after his 1978 Volkswagen went off Old Court House Road near Creek Crossing Road and struck a tree, police said. Peter Lisenby of 2447 Gallows Rd. died at Fairfax Hospital, police said. The cause of the accident was under investigation.