FRISCO, Texas (AP) — Police in a Dallas suburb have concluded that heat stroke caused the death of former Dallas Cowboys running back Marion Barber III.

In a statement Monday, Frisco police say the Collin County medical examiner ruled Barber’s death an accident.

Police provided no further elaboration, and the medical examiner’s office didn’t immediately respond to messages from The Associated Press.

Police making a welfare check on June 1 found the 38-year-old former running back dead at a Frisco apartment.

Following his death, the Dallas Cowboys released the following statement:

“We are heartbroken by the tragic death of Marion Barber III. Marion was an old-school, hard-nosed football player who ran with the will to win every down. He had a passion for the game and love for his coaches and teammates. Our hearts go out to Marion’s family and friends during this difficulty time.”

Barber, nicknamed “Marion the Barbarian” spent six seasons with Dallas and one with the Chicago Bears. He made the Pro Bowl in 2007.

He would have turned 39 on June 10.