Each of the 58 fatal victims of the Oct. 1 mass killing during the Route 91 Harvest festival on the Las Vegas Strip died from gunfire, Clark County officials have announced.

Eighteen of the victims were shot in the head, according to a list provided by the Clark County Coroner’s office more than 11 weeks after a gunman broke two windows and opened fire from his 32nd-floor room in the Mandalay Bay, causing the worst mass shooting in modern U.S. history.

More than 500 people also were injured. The gunman, Stephen Paddock, a 64-year-old Mesquite resident, took his life before Metro Police officers breached his two-room suite, the Las Vegas Sun reports.

He shot himself in the head, officials said.