"It was a pretty impressive scene to pull up on," Fire District Assistant Chief Lee Bucklin told KVOA Tucson. "You could see vehicle parts all over. There were people thrown all over the place."
The Arizona Department of Public Safety closed the highway so four helicopters could land. First responders considered it a mass casualty situation. All of the survivors had to go to the hospital.
"I don't think you really ever get used to it," Bucklin said. "You learn how to deal with it. You know you have a job to do. You just focus on your job. Fade out everything else."
The SUV was registered to a person in Sierra Vista, Arizona, according to Bucklin. The circumstances of the pursuit by Border Patrol are unknown at this time.