Colt Brennan, the former University of Hawaii star quarterback, died at the age of 37 on Tuesday. Brennan’s father, Terry, confirmed to the Hawaii Star-Advertiser that he actually passed away in California on Monday. He was being treated at a rehabilitation facility when he was found unconscious a few days ago.

“He was doing so well, the spark was back in his eyes, and he was healthy and doing great, and it happened,” Terry Brennan told the Adviser. “These guys were no-nonsense guys. It just got away from him. I don’t know how else to explain it. Maybe one day I’ll be able to explain it better.”

According to Terry Brennan, Colt died “peacefully” with family members by his side.