A school bus slammed into two vehicles at an intersection, killing two people in the cars and injuring 23 elementary students who were headed to class in the morning.

Two children were taken to hospitals with life-threatening injuries after the Monday crash.

Some of the children suffered head injuries, cuts, scrapes, broken bones and neck injuries, said Laura Fitzmaurice, head of the emergency department at Children's Mercy Hospital (search) in Kansas City. Many were bleeding and crying for their parents.

"One little boy had his teeth knocked out and he asked me if he was going to be deformed," said a shaken Vickie Whattoff, one of about 20 workers from a nearby grocery store who responded.

She said many of the injuries appeared to be from "kids flying forward and hitting the seat in front of them."

Investigators said they don't know why the bus suddenly veered into the cars, which were waiting for a stoplight to change in this community about 15 miles north of Kansas City.

The cars were nearly demolished. The victims were identified as David Gleason, 53, of Kansas City, and David Sandweiss, 49, of Liberty, police said. They were the only people in the vehicles.

Police said 23 students were taken to three area hospitals with injuries and the others were taken to the school or released to their parents.

"It's a worst nightmare," Liberty School Superintendent Scott Taveau said. "This is a tragedy for this community."

The bus was taking 53 kindergartners through fifth-graders to Ridgeview Elementary School (search) when the crash happened about 8:30 a.m. The students ranged in age from 6 to 11.

The bus driver, whose name was not released, was being treated at a hospital Monday. Taveau said the driver was a seven-year veteran driver who had "an impeccable record."