A Missoula County Detention Center inmate, Brian Dewer Bowker, 54, collapsed and died while in custody Sunday morning.

Missoula County Sheriff T.J. McDermott said the incident occurred shortly after breakfast on Sunday morning.

"The 54 year-old inmate collapsed in his cell," McDermott said. "He reported to his cellmate just prior to collapsing that he believed he was experiencing some kind of medical event. Our detention officers provided medical aid and treatment while awaiting an ambulance, which later transported him to a local hospital where he was pronounced dead."

McDermott explained how the investigation into Bowker's death would be conducted.

"His body is going to be sent to the State Crime Lab in Missoula for an autopsy," he said. "Then, because the inmate was in custody at the time of his death, we've contacted the Missoula City Police Department, and they're going to be conducting an investigation into the incident."

According to the Missoula County Jail roster, Bowker was arrested in October of 2014 on charges of criminal endangerment and aggravated DUI. He was being held on $50,000 bond.