By Genevieve Judge, Local News 8 Reporter 

BANNOCK COUNTY - One of four charter buses carrying students from a marching band from American Fork, Utah crashed on the southbound side of I-15, two miles north of McCammon in Bannock County at 7:16 p.m. Saturday night. 

Idaho State Police say Heather Christensen, 33, of Spanish Fork, Utah died at the accident.  Parents say she was the woodwind instructor for the group.

The band's director tells the Salt Lake Tribune that Christensen died trying to save her students. John Miller says she tried to grab the steering wheel when the bus driver lost control, but fell out of a window when the bus rolled.

"Apparently the driver had blacked out.  Had a medical condition and someone on the bus had tried to help steer to get the bus back on the road before it went off the highway," said Gary Wilson, a father of an American Fork High School band member.

Students told investigators that they're holding Heather Christensen up as a hero because she tired to keep the bus on the road before the crash.

12 students were transported to Portneuf Medical Center by ambulance and two others by Life Flight helicopter.  There were a total of 46 band members, two adult chaperones and the driver on board the bus when it crashed.

The students from American Fork High School were taking part in the Idaho State University Band Invitational Competition at Holt Arena in Pocatello before the accident happened.  They had just won the competition.

Dayley says there were no life-threatening injuries for the students involved in the crash.  All of them were taken to Portneuf Medical Center in Pocatello to be checked out.  As of 6 p.m. Sunday night, all of the students had been released from the hospital except one.  The bus driver is also still at Portneuf Medical Center. 

Dayley also added that they are unsure of the cause, but it could be due to a pre-existing medical condition that the bus driver had. "Preliminary investigations indicate that the bus driver, Debra Jarvis, 50 year-old female out of Spanish Fork Utah, suffered some type of medical condition and the bus started to go off the road," said Captain Dayley. 

"This is going to be a lengthy investigation.  We probably won't have a report out for at least a couple of weeks," said Dayley.  Idaho State Police said blood and urine samples were taken from Jarvis, as is customary in fatal accidents. The result will likely take weeks.

"My daughter was sitting in the first row of the bus.  She saw it.  But I think that tomorrow (Sunday) it will really hit home.  Hard.  Very hard," said Ellen Wilson, a mother of an American Fork High School band member.  "Monday is going to be extremely difficult for the kids.  Extremely," said Ellen.

Heather Christensen was employed by American Fork High School.  The bus driver, Debra Jarvis, was employed by Lake Shore Motor Coach Lines.  The bus is registered to Lake Shore Motor Coach Lines Inc., from Provo, Utah.

Idaho State Police was assisted by the Bannock County Sheriff's Office, Bannock County Search and Rescue, Idaho Transportation Department, Inkom Police Department, Pocatello Ambulance, Lava Hot Springs Ambulance and Inkom Quick Response Unit.