CITRA, Fla. -- A big rig driver who rear-ended a school bus, killing a 13-year-old girl and injuring eight other students, was on his cell phone before the crash, according to a Florida Highway Patrol report.

According to the FHP report, Reinaldo Gonzalez, 30, of Orlando, told investigators that he was on the phone before his rig slammed into the bus, WJXT's Vickie Pierre reported on Wednesday.

The bus was apparently stopped with its flashers engaged and students exiting when it was struck from behind. The big rig hit the bus and pushed it hundreds of feet before both vehicles caught fire, investigators said.

Gonzalez "said that he was using the phone just prior to the crash and he looked up and noticed that the bus had stopped," said FHP Lt. Pat Riordan. "It was certainly a distraction."

James Horton saw the wreck.

"I saw the bus stop and flashing lights on. Then the semi slammed into it with no hesitation and no stopping. It burst into flames," Horton told WFTV-TV.

The FHP report lists driver distraction, careless driving and faulty brakes as contributing causes of the crash.

Motorists 'Jump Into Inferno' To Rescue Children

Officials said the bus carrying 21 students from North Marion Middle School and North Marion High School was struck by the tractor-trailer Tuesday afternoon on U.S. Highway 301 at 155th Street near Citra.

As flames began to overwhelm the bus, four motorists stopped and began pulling the trapped students out of the flames.

"The Lord put us all there for that reason -- to save those children," said Horton, a father of three.

Marion County School Superintendent Jim Yancey called the bystanders who helped get children off the burning bus "heroes."

"(The motorists) started pulling people out of the bus, there were four of them, and they kept trying to go back and get more and more kids and they said finally it just got too hot and they couldn't pull anymore of kids out," Yancey told WKMG-TV.

The rescuers who had done so much were visibly grieving for the one student they couldn't help.

"The kid was lodged and I just couldn't get her out," said Chris Mann, an elevator installer who stopped to help. "There was nothing I could do."

Marion County Schools Mourn Girl's Death

The Florida Highway Patrol identified the student killed as Frances Schee. She was apparently trapped inside the burning bus.

"It was very hot. It smelled really bad, and I was scared because I couldn’t get off and the fire was just coming," said Natalya Mitchell, a seventh-grade student who was on the bus at the time of the crash. "All we saw was a big truck come and hit -- and the fire."

The girl said she knows she's fortunate to be alive, but said she cannot believe her friend Frances is gone.

"I wanted somebody to help her, but nobody really could," Mitchell said.

Grief counselors were at several Marion County schools on Wednesday morning, meeting with students and faculty.

One of Frances' teacher remembered her for her positive spirit.

"At the end of the day, I would see Frances and she would smile and she would have something wonderful to say," Sarah Netwood said. "She was very popular. She’s the kind of student that all teachers wanted to have."

Frances was involved in several school activities, including playing clarinet in the school band.

"It is just a really sad day for Marion County schools," Yancy said. "Those 18 kids who got out of there alive are very fortunate to get out of there alive. This is a tragedy but it is also a miracle."

A funeral service for Frances will be held at Jarvey Grant Park on Sunday at 10 a.m.