A U.S. Naval Academy junior and three District residents died in traffic accidents in the region over the weekend, police said.

Anne Arundel County police said John M. Marshall, 20, a midshipman from Simsbury, Conn., died at the University of Maryland Shock Trauma Unit in Baltimore about three hours after a crash yesterday morning in Millersville, Md.

Marshall and three other midshipmen were riding in a car that struck another vehicle at Rtes. 3 and 178 about 12:30 a.m., police said.

Two midshipmen were listed in critical condition yesterday at the Baltimore hospital; the third was reported in satisfactory condition at North Arundel Hospital.

Meanwhile, Prince George's County police said Thomas L. Milton, 48, of 3207 21st St. SE, was killed in Fairmount Heights early yesterday when he was hit by a van while crossing the street.

Milton was trying to cross Sheriff Road shortly after 1 a.m. when the accident occurred, police said. The driver of the van swerved in an attempt to avoid Milton but struck Milton and a parked car, police said.

The driver was not injured or charged in the accident.

In Montgomery County, state police said William Ghormley, 77, of 3604 Massachusetts Ave. NW, died Saturday after being involved in an accident in Damascus.

Ghormley's car collided with a truck as he tried to turn around on Rte. 27 just before 2:30 p.m., police said.

They said he died later at Montgomery General Hospital apparently of a heart attack, but it was unclear yesterday whether he was stricken at the time of the accident or afterward.

District police said a 40-year-old man died of internal injuries after being run over by a car Saturday night in the street outside his home at 5401 Drake Place NE.

The victim, Joseph Tyson, apparently had fallen into the street or was out of the driver's sight when the accident occurred, police said.