Two Washington area residents were killed yesterday in separate automobile accidents, Fairfax County and District police reported yesterday.

The first accident occurred shortly after 6 a.m. when a car driven at an "exceptionally" high speed by a 21-year-old Arlington woman crashed into the fountain in the center of Chevy Chase Circle in Northwest, according to D.C. police.

They said Adrienne Dee Adams, 1112 N. Quantico St., was driving north on Connecticut Avenue when she apparently lost control of her car; it slammed into the 18-inch-thick, two-foot-high wall of the fountain.

She was pronounced dead at the scene.

A 21-year-old Washington man was killed in an accident that occurred about 11 a.m. in West Springfield when the car he was driving struck a tractor-trailer truck head-on, according to Fairfax County police spokeswoman Carol Kitzerow.

She said Bernard V. Lathern, of 1209 Valley Ave. SE, was traveling south on Industrial Road near Edsall Road when his car crossed over to the northbound lane and crashed into the truck. He was pronounced dead a short time later at Fairfax Hospital.

The driver of the truck received minor injuries, Kitzerow said She said Lathern was not wearing a seat belt.