(CHICAGO) An 84-year-old man’s death following a garage explosion last week in the Far South Side Morgan Park neighborhood has been ruled a homicide.

About 4 a.m. Tuesday, Henry S. McCann Jr. saw someone in the backyard trying to break into the garage of his home in the 11200 block of South Green Street, according to Chicago Police and the Cook County medical examiner’s office.

McCann went outside to investigate, and the male ran away. When the elderly man opened the door to check the garage, something inside exploded, authorities said.

He taken to Roseland Hospital with burns and later transferred to Stroger Hospital, where he was pronounced dead at 4 p.m. Friday, authorities said.

An autopsy Sunday found McCann died of complications of thermal injuries, with heart disease listed as a secondary cause.

The fire from the explosion spread to three other garages, police said. Chicago Fire Department officials could not immediately provide more information.

No one was in custody Sunday afternoon as CPD’s Bomb and Arson Unit investigates.