Tenn. school bus driver to mom: "I hope it's not my fault"

The investigation into the deadly Tennessee school bus crash is focused on speed and the actions of the driver. Dazed members of the Chattanooga community are mourning the loss of five children – a kindergartner, a first grader and three fourth graders.

Twelve students are still receiving treatment at the Children’s Hospital in Chattanooga -- six in critical condition.

The investigation into the deadly wreck has turned to the bus driver, 24-year-old Johnthony Walker, who faces multiple charges. Walker’s mother said she spoke to him after the crash, reports CBS News correspondent Manuel Bojorquez.

“He said, ‘I love you mom, I’ve been in an accident on the bus’ and he said, ‘Mom there are kids dead, I hope it’s not my fault,’” she said.

Charged with five counts of vehicular homicide, police say Walker was driving well over the 30-mile-per-hour speed limit. He received his commercial driver’s license in April and was involved in a minor bus crash just two months ago.

Walker has no criminal history and the results of tests for drugs and alcohol in his system are still pending. The bus company that hired him – Durham School Services – said they are working with investigators, but did not address our questions about reports that parents here had complained about Walker.

The NTSB is looking through the mangled wreckage and will examine the bus’s black box to help determine the driver’s actions leading up to the crash. They’ll also look into whether seat belts -- which the bus did not have -- could have prevented deaths.

“The bus was not equipped with passenger seatbelts. Our mission is to understand not just what happened, but why it happened,” said NTSB Chairman Christopher Hart.

Only six states require seat belts on school buses. Tennessee is not one of them. Nationwide an estimated four children die every year in large school bus crashes.

Jasmine Mateen recalled the agony when she learned her six-year-old daughter Zyaira was among the five children killed on a Woodmore Elementary school bus.

“The detective asked me what my child had on and said your baby’s deceased. She wanted to be a doctor. And now my baby can’t be that doctor that she wanted to be,” the tearful mother said.

At a vigil Tuesday night, people released balloons into the air. Parents in this stunned community are struggling with how to explain this tragic news to their children.   

“It’s just so sad -- no words,” said one parent.