17-year-old male, a student at O'Conner High School, critically injured, after he is struck by a tractor-trailer on Leslie Road in San Antonio, while getting in a friend's car to go to school.

A 17-year-old boy is in critical condition at a San Antonio, Tex., hospital after he was struck by an 18-wheeler and dragged along a road as he walked to school early Monday.

The junior at O'Connor High School in Helotes, suffered "significant injuries" and was in surgery at University Hospital at around noon, school and police officials said.

His name was not released.

Authorities said the boy was walking to school along Leslie Rd. at around 8:30 a.m. when a friend stopped and offered him a ride.

The boy stepped out into the road and was hit by an 18-wheel gravel truck, school district spokesman said.

San Antonio Police Sgt. Javier Salazar said the driver swerved to avoid the boy, but hit another car, which jolted the truck back toward the teen.

The boy was dragged for some 40 feet before the tractor-trailer stopped.

He remained pinned under the struck for some time before crews managed to free him, said police

A handful of the boy’s friends witnessed the accident, as did a teacher, who rushed in to help.

"They were quite traumatized by it," said a school spokesman.

The boy's parents and a school administrator were with him at the hospital, Gonzalez said.

The driver has not been charged.

"It looks like an unfortunate accident," Salazar said, adding that the truck belonged to a business located on Leslie Rd.

Some 3,000 students attend O'Connor High, named for retired Supreme Court Justice Sandra Day O'Connor.

Classes at the school went on as planned Monday and grief counselors were on hand, Gonzalez said.