An autopsy Friday on a security guard at Thornwood High School, who died after trying to break up a fight between two students, was unable to determine a cause of death, according to the Cook County medical examiner’s office.

More tests will be required to pinpoint how Richard Cowser, 54, of South Holland, died, according to the office.

South Holland police said Friday they had no additional information to provide regarding Thursday’s altercation between two female students at the school, 17101 Park Ave.

Cowser and another security guard were called to break up the fight, and Cowser fell against a locker and was injured, according to police.

South Holland paramedics were initially called to help him because he was unconscious and having trouble breathing, police said.

Mike Nolan