At least nine people were killed and up to 40 people are feared dead after a three-alarm fire broke out during a concert in Oakland on Friday, authorities announced on Saturday morning.

Fifty to 100 concertgoers were inside the building when the blaze began around 11:30pm local time. Alameda County Sheriff's Sergeant Ray Kelly said that he expects the number of deaths to rise in the coming hours.

"A majority of the fatalities were found up on the second floor," the city’s Fire Chief Teresa Deloach-Reed told reporters. "It must have been a very fast-moving fire."

“We still have to do a more thorough search of the building and we don’t know the potential number of other victims,” Deloach-Reed explained, adding that no firefighters were injured while fighting the blaze. She also said that firefighters found no evidence that fire alarms were activated while the fire spread.

The show was hosted by 100% Silk, a Los Angeles-based electronic label, including Golden Donna, Cherushii, and Nackt.

Warehouse Fire Kills Several People At Dance Party In Oakland Show all 11 1 /11 Warehouse Fire Kills Several People At Dance Party In Oakland Warehouse Fire Kills Several People At Dance Party In Oakland OAKLAND, CA - DECEMBER 03: Firefighters investigate the scene of a overnight fire that claimed the lives of at least nine people at a warehouse in the Fruitvale neighborhood on December 3, 2016 in Oakland, California. The warehouse was hosting an electronic music party. (Photo by Elijah Nouvelage/Getty Images) Getty Images Warehouse Fire Kills Several People At Dance Party In Oakland OAKLAND, CA - DECEMBER 03: The face of a building that was the scene of a overnight fire that claimed the lives of at least nine people at a warehouse in the Fruitvale neighborhood on December 3, 2016 in Oakland, California. The warehouse was hosting an electronic music party. (Photo by Elijah Nouvelage/Getty Images) Getty Images Warehouse Fire Kills Several People At Dance Party In Oakland OAKLAND, CA - DECEMBER 03: Charred windows on the face of a building that was the scene of a overnight fire that claimed the lives of at least nine people at a warehouse in the Fruitvale neighborhood on December 3, 2016 in Oakland, California. The warehouse was hosting an electronic music party. (Photo by Elijah Nouvelage/Getty Images) Getty Images Warehouse Fire Kills Several People At Dance Party In Oakland OAKLAND, CA - DECEMBER 03: Oakland Fire Chief Teresa Deloach Reed speaks to the press following an overnight fire that claimed the lives of at least nine people at a warehouse in the Fruitvale neighborhood on December 3, 2016 in Oakland, California. The warehouse was hosting an electronic music party. (Photo by Elijah Nouvelage/Getty Images) Getty Images Warehouse Fire Kills Several People At Dance Party In Oakland OAKLAND, CA - DECEMBER 03: The face of a building that was the scene of a overnight fire that claimed the lives of at least nine people at a warehouse in the Fruitvale neighborhood on December 3, 2016 in Oakland, California. The warehouse was hosting an electronic music party. (Photo by Elijah Nouvelage/Getty Images) Getty Images Warehouse Fire Kills Several People At Dance Party In Oakland OAKLAND, CA - DECEMBER 03: Firefighters investigate the scene of a overnight fire that claimed the lives of at least nine people at a warehouse in the Fruitvale neighborhood on December 3, 2016 in Oakland, California. The warehouse was hosting an electronic music party. (Photo by Elijah Nouvelage/Getty Images) Getty Images Warehouse Fire Kills Several People At Dance Party In Oakland Firemen assess the scene where a fire tore through a warehouse party early this morning in Oakland, Calif. on December 03, 2016. At least 9 people were killed in the blaze.(AP Photo/Josh Edelson) AP Warehouse Fire Kills Several People At Dance Party In Oakland OAKLAND, CA - DECEMBER 03: Firefighters investigate the scene of a overnight fire that claimed the lives of at least nine people at a warehouse in the Fruitvale neighborhood on December 3, 2016 in Oakland, California. The warehouse was hosting an electronic music party. (Photo by Elijah Nouvelage/Getty Images) Getty Images Warehouse Fire Kills Several People At Dance Party In Oakland OAKLAND, CA - DECEMBER 03: The face of a building that was the scene of a overnight fire that claimed the lives of at least nine people at a warehouse in the Fruitvale neighborhood on December 3, 2016 in Oakland, California. The warehouse was hosting an electronic music party. (Photo by Elijah Nouvelage/Getty Images) Getty Images Warehouse Fire Kills Several People At Dance Party In Oakland OAKLAND, CA - DECEMBER 03: Charred windows on the face of a building that was the scene of a overnight fire that claimed the lives of at least nine people at a warehouse in the Fruitvale neighborhood on December 3, 2016 in Oakland, California. The warehouse was hosting an electronic music party. (Photo by Elijah Nouvelage/Getty Images) Getty Images Warehouse Fire Kills Several People At Dance Party In Oakland OAKLAND, CA - DECEMBER 03: Firefighters investigate the scene of a overnight fire that claimed the lives of at least nine people at a warehouse in the Fruitvale neighborhood on December 3, 2016 in Oakland, California. The warehouse was hosting an electronic music party. (Photo by Elijah Nouvelage/Getty Images) Getty Images

Authorities confirmed that the scene of the deadly fire was under investigation for trash violation and illegal construction. Investigators are also looking into whether people were illegally living in the warehouse-turned-art studio.

“The whole building was divided up into small areas that were basically work areas for artists,” Deputy Fire Chief Mark Coughlin told reporters at the scene of the blaze on Saturday afternoon. “So it ranged from people doing woodworking to people doing sculpting to people doing kinetic art.”

When local firefighters arrived at the scene they encountered the only staircase in the building—a makeshift structure build with wooden pallets—that quickly engulfed into flames.

“It was too hot, too much smoke, I had to get out of there,” Bob Mule, a resident who lives in the building, told the East Bay Times, adding that he suffered minor burns and witnessed someone jumping from the building’s second-floor window. “I literally felt my skin peeling and my lungs being suffocated by smoke. I couldn’t get the fire extinguisher to work.”

Friends and family members of those missing are currently searching for information on the event’s Facebook page. Organizers have also compiled a list of the names of concertgoers unaccounted for.