Smoke inhalation killed all 36 people who died in a December fire at a warehouse in Oakland, Calif., investigators said.
The cause of death were confirmed Saturday by the Alameda County Coroner's Bureau.
The fire broke out Dec. 2 during a concert, trapping scores of people. The warehouse _ known as the Ghost Ship _ had an internal maze of structures, according to firefighters and former tenants, making it difficult for people to escape.
The victims ranged in age from 17 to 61.
Despite mounting evidence that the warehouse had been converted into an illegal residence and music venue, the city of Oakland never moved to shut it down, records show.
The city had received several complaints that conditions inside the warehouse were unsafe, including reports of piles of trash and faulty electrical wiring.
The Alameda County district attorney's office has opened a criminal investigation into the fire.
The San Francisco Chronicle first reported the causes of death, which were determined in December.
