CHATTANOOGA, Tenn. (CBS News/AP) – A school bus driver charged with vehicular homicide in a crash in Tennessee asked the children if they were ready to die, according to the mother of three kids who were aboard the bus. One of her children was among the five dead.RELATED: Chattanooga crash that killed 5 children revives debate over school bus seat belts

“My daughter said right before the bus flipped that he was speeding around the curve and asked them ‘Are y’all ready to die,’”Jasmine Mateen told CBS News correspondent Mark Strassman. Mateen’s 6-year-old daughter was killed.RELATED: School bus driver charged in Chattanooga bus crash that killed at least 5 children

Mateen also said she had complained repeatedly since August about the driver’s behavior before the accident, to no avail. She said that just last week the driver allegedly told the kids: “Shut the F up, I have a hangover,” and another time forced the kids to ride in scorching heat with the windows rolled up.

Mateen said the daughter who passed was sitting next to another of her children, and claims to have seen the child “smushed” between seats after the crash. The daughter who survived said after the crash repeatedly, “I miss her.”

“I’m angry. I’m hurt,” Mateen said, adding that her deceased daughter wanted to be a doctor.

One student who was on the bus told CBS Chattanooga affiliate WDEF-TV the driver “wasn’t paying attention and was going real fast.”RELATED: At least 5 students killed in Chattanooga school bus crash

Other parents say they complained about the driver in the past. Craig Harris, a parent of two children who were on the bus, told ABC’s “Good Morning America” that the bus driver sometimes drove too fast.

“There has been times where I’ve seen him going a little faster than he probably should be going,” Harris said. He said his daughter and stepson were in shock and pain after the crash.

Johnthony Walker, 24, is being charged with five counts of vehicular homicide, reckless endangerment, and reckless driving over the accident.

Officials say he was apparently speeding along a narrow, winding road when he wrapped his vehicle around a tree. The bus was carrying 35 children from Woodmore Elementary School, authorities said. The students in kindergarten through fifth grade, when it crashed about 3:30 p.m., turned on its side and wrapped around a tree.

The wreck Monday afternoon plunged the city of Chattanooga into mourning, with parents stricken by the news and people lining up to donate blood.RELATED: GPS tracking system connects Nash-Rocky Mount buses with parents

“The most unnatural thing in the world is for a parent to mourn the loss of a child,” Mayor Andy Berke said. “There are no words that can bring comfort to a mother or a father. So today, the city is praying for these families.”

In court papers, police said Walker was driving well over the posted 30 mph limit when he lost control of the bus. He was jailed on $107,500 bail for a court appearance Nov. 29 on charges that also included reckless driving and reckless endangerment.

Emergency crews needed almost two hours to get all the youngsters off the bus. Bloodied children lay on stretchers, while others walked away dazed with their parents. More than 20 injured students were taken to the hospital, police said.

Twelve remained hospitalized Tuesday, six in intensive care, said Kirk Kelly, interim school superintendent.

Three of the children killed were in fourth grade, one was in first grade and another in kindergarten, Kelly said. Their families were notified, but their names were not released.

The National Transportation Safety Board sent a team to investigate, and police obtained a warrant to remove the bus’ black box, which contains data on the vehicle’s movements.

The driver was employed by an outside bus contractor, Durham School Services. Walker appeared to have no criminal record in Tennessee, state and local authorities said.

David A. Duke, the CEO Durham School Services, issued a statement on Twitter saying the company was “devastated” by the accident and is working with police and school officials to investigate.

NTSB chairman Christopher A. Hart said investigators will focus first on gathering witness accounts and other evidence. He said investigators would also check on whether the bus had cameras.

Counselors were on hand for the students and staff as classes resumed at the elementary school. Pastor Tavner Smith and a dozen staffers of the Venue Church went to offer support.

“It’s devastating,” Smith said. “You send your kids to school and think you’re going to see them that evening. We’re really just praying for all the families right now, for what they’re going through.”