BAGHDAD, Iraq (AP) – A 62-year-old prisoner at the notorious Abu Ghraib prison died of an apparent heart attack, the U.S. military said Friday.

Detainees being held in the same compound as the man notified guards that he was having difficulty breathing, a statement said. The prisoner died Thursday at the onsite medical facility after efforts to revive him failed, it said.

The military is investigating the incident, which is common procedure after all detainee deaths, the statement said.

Abu Ghraib is the same site where American soldiers abused Iraqi prisoners after the U.S.-led invasion of Iraq three years ago.