An Adams 12 school bus driver made no apparent attempt to correct the vehicle's course before it crashed into a support pillar at Denver International Airport on Sunday afternoon, according to Denver police.
The bus was transporting football coaches and players from Legacy High School. The driver was killed, and two people remained in critical condition on Monday.
The driver was Kari Chopper, according to the Denver Office of the Medical Examiner. She died of blunt-force injuries. She was 43 and had worked for the school district for four years.
Three coaches were seriously injured in the crash, according to the school district. They are Wayne Voorhees, Matt Kroupa and Kyle Rider. Voorhees is the head football coach and has worked at Legacy since 2000, according to his LinkedIn.
Fifteen students were hospitalized, but all have been released to their families, according to the district. Other students were not hospitalized; 28 people in all were aboard the bus, according to an airport spokesman.
What we know about the crash:
The bus driver picked up a group of Legacy High School football players and coaches from the airport's eastern passenger pickup. The bus headed for the airport exit on Peña Boulevard before looping back around to the terminal, said Denver police Sgt. Mike Farr.
The bus was the lead vehicle of a three-bus caravan that was transporting the team home after a game in California. Neither of the two other vehicles looped back around.
"I’m told by witnesses that they were ready to go home," Farr said. " ... Nobody could tell me certainly why the bus driver made that turn."
The bus was traveling back toward the passenger pickup when it drove off the right side of the road, straight into a bridge support pillar.
"The tire tracks did not show any sign of left or right turns," Farr said. Most witnesses guessed that the bus was traveling at 30 to 40 mph, significantly over the speed limit. The front end of the vehicle was severely impacted.
The passengers seemed to have little warning of the impending impact. One witness didn't hear any shouting or exclamations before the impact, the Denver Post reported.
What's next:
"What we're left with now is trying to explain why the crash occurred," Farr continued.
Investigators are now looking into whether any mechanical failure within the bus could have caused the crash, whether the driver may have had a medical condition or whether it may have been an intentional act. The driver passed a medical examination related to her job in May, according to the district.
There is no indication any other vehicle cut off the bus or otherwise interfered with the driver.
Farr said it will take at least six to eight weeks to get toxicology results and determine whether drugs or alcohol played a role.
Farr said school district is fully cooperating with the investigation. Police also will be interviewing family members of the driver to see if they can provide any insight.
"Quite frankly there is a big mystery there we are trying to solve," he said. "We may not get all the answers. One of our most important witnesses would be the driver."
The Associated Press contributed to this report.