Ten other children and the bus driver suffered minor injuries in the 8:30 a.m. crash. All were expected to be treated at Ephrata Community Hospital and released.

The child with the more serious injuries was taken to Lancaster General Hospital and then transferred to Hershey Medical Center for further treatment, a school official said.

The students were on a bus headed to Blue Ball Elementary School when the accident happened. The collision occurred near the intersection of Route 322 and Groff Lane, east of Blue Ball, in the village of Beartown.

The students, second- to sixth-graders, were checked for head and neck injuries after the accident, said Eastern Lancaster County School superintendent Robert Hollister.

Nine ambulances responded to the accident. Emergency workers took some of the children off the bus on backboards after fitting them with neck braces, said Hollister, who praised the emergency response.

Hollister also praised the school bus driver, Denise Wilimzig, 38, of New Holland, for her quick actions during the accident.

The bus was stopped and a student was about to get on board when it was hit from behind, the superintendent said.

"The driver heard the brakes of the truck and yelled for the kid to get away," he said. "The kid would have been stepping on the bus at the moment of impact. The bus driver's quick actions prevented some serious injuries."

Wilimzig, who works for Brightbill Transportation, was thrown into the steering wheel by the collision, Hollister said.

The driver of the box truck was James Rhoads, 73, of Reading, state Trooper Nelson Renno said. The truck was from Tab Industries in Reading.

Rhoads was cited for careless driving after the collision, Renno said.

Hollister said the students stayed calm after the accident.

"It's a difficult situation," he said. "It's very scary when you start to take kids out of the back of the bus."

Parents of injured students were notified, he said. Sixteen students on the bus who were not injured continued to to school, where they were checked by a school nurse.