AMERICAN FORK – Clad in flip flops, and cradling her clarinet in her arms, American Fork High School junior Haylie Lund, 17, is wide-eyed as she recounts Saturday's bus accident that killed her band instructor.

"Inside, it was just chaos. Everyone was screaming and getting thrown around like rag dolls," Lund told the Deseret News, during marching band practice after school Monday.

Woodwinds instructor Heather Christensen, 33, an American Fork High alumna, was killed when the tour bus carrying about 50 of the band students veered off Interstate 15 about 50 miles north of the Idaho-Utah border, near McCammon, Ida., Saturday night.

The group was returning from a competition they had won at Idaho State University in Pocatello.

Christensen, lauded as a hero in her death, grabbed the wheel after the bus driver blacked out and the vehicle began to veer.

"If she hadn't jumped and saved that bus of kids, my sister would be dead. And that gives me chills all up and down my spine," said 16-year-old Elizabeth Masson, an American Fork High junior whose sister, Kendra, also 16, was on the bus that tipped over.

All of the bus passengers were taken to the hospital to be checked. Most suffered minor injuries such as cuts and bruises. The driver and several students were hospitalized with more serious injuries.

Drum major Deborah McKinney, 17, a senior, was sporting three stitches across the bridge of her nose Monday. "I hit my head on the seat, and then was thrown onto broken glass," she said.

The last student was discharged from the hospital Monday. Bus driver Debra Jarvis, 50, was discharged Sunday.

The atmosphere at the school Monday was somber and supportive, with some teens crying, students told the Deseret News.

Students dressed in their Sunday best and also donned flip-flops because Christensen loved the casual footwear. By the end of the day, a bench at the front of the school was covered with balloons, flowers and candles.

Lund recalls the students were traveling south in a caravan of four buses. "We were watching a movie, `Better Off Dead', that Heather (Christensen) had picked. She yelled something and I thought she was making a joke about the movie because that was something she would do," Lund said.

But, Christensen was calling to the driver as the bus was veering off the road.

Christensen dove for the wheel, Lund said. "I looked out the window and we were going off the road. We hit a large bump and everyone went flying in their seats. I was so scared. I was terrified," she said. "The bus came down head first, then hit on its side, then slid for a while."

There was screaming and confusion, Lund said.