Four Denver officers who had just came back from escorting East High School students from Wednesday's Ferguson protests were hit by a car and one remains in critical condition, the Denver Post reported on Thursday.
The officers were flung to the sidewalk and the car that hit them left a trail of wreckage that included the police gear, their blood and a helmet.
The most injured officer was dragged by a black Mercedes dozens of yards, and finally settled on a curb where he lay critically injured.
"He was just lying there," Taylor Ellison, a sophomore at the high school, said of the officer. "His pants were ripped. He wasn't moving."
Ellison added that he thought the officer was dead because of how badly he was injured.
Officer John Adsit, the injured officer, had surgery Wednesday night. While the officer will undergo further surgeries, the most critical issues have been dealt with, the police department said, KKTV reported.
The crash is believed to be an accident, with the driver suffering a medical emergency while driving the vehicle.
"We do not believe this is an intentional act, and we have no reason to believe it is related to the protests," DPD Commander Matt Murray said.
Adsit and two other injured officers have been on the force for nine years. The fourth officer has been on the squad for 17 years. They all ride bicycles for the department in the area where the crash occurred.
The students were participating in a walk-out in protest of the grand jury's decision to not indict Ferguson officer Darren Wilson in the death of Michael Brown. They were all on their way back to school when the officers were hit.