A 16-year-old Herndon youth was charged with reckless driving yesterday in connection with an accident in which two Great Falls children were killed when the pickup truck driven by the youth hit the family's car and pushed it beneath a school bus, Fairfax County police said.

The youth's name was not released because he is a juvenile.

Fairfax Commonwealth's Attorney Robert F. Horan Jr. said yesterday that under Virginia law, the only possible charges in this type of case are reckless driving and manslaughter, and that manslaughter must involve a willful, wanton, reckless disregard for life.

"There is no evidence of that" in this case, Horan said.

The accident occurred about 8:30 a.m. April 22 on Springvale Road in Great Falls, where the school bus was stopped in the road waiting for a truck to turn around.

Pamela Sue Grinder, a 38-year-old Arlington teacher who was taking her 7-year-old daughter to school, pulled up behind the bus in the family's station wagon.

Police said a pickup truck driven by the youth came over a hill and hit the station wagon from behind, pushing it underneath the bus, in which 12 first- and second-graders were riding.

Horan said that, contrary to some initial reports from police, there was no proof that the youth had been speeding.

Killed in the accident were Bethany J. Grinder, 7, and her sister, Brittany, 2. Pamela Sue Grinder was admitted in critical condition to Fairfax Hospital with head and abdominal injuries. She was discharged on May 14, according to a hospital spokesman.

The accident prompted a group of Great Falls residents to seek safety improvements on roads in the area. The group came up with 14 recommendations, including more three- and four-way stops at some intersections, reduced speed limits in some areas and shoulders on roads, said one resident, Thomas Lion.

The state highway department is considering the proposals and is scheduled to meet with residents on the issue tonight, Lion said.