California officials fear up to 40 people have been killed in a massive fire that happened Friday night during a concert inside a building in Oakland.

Nine people have been confirmed dead and 25 others remain missing. Fire crews have still not entered the building as of Saturday afternoon.

“We did not have a lot of victims go to the hospital,” Sgt. Ray Kelly, spokesman for the Alameda County Sheriff’s Office, told reporters during a news conference Saturday. “It appears that people either made it out, or they didn’t make it out.”

The three-alarm fire was reported at about 11:30 p.m. Friday at a building off 31st Avenue and International Boulevard, about three miles outside of downtown Oakland, according to the Oakland Police Department.

The fire broke out during a party featuring musician Golden Donna’s 100% Silk West Coast Tour. Oakland Fire Chief Teresa Deloach-Reed told The Washington Post that more 50 people were inside the building, a warehouse known as Oakland Ghost Ship, which has been turned into multipurpose venue for artist exhibits and parties.

The fire is not being investigated as a crime, Officer Johnna Watson, spokeswoman for the Oakland Police Department, said Saturday.

Questions are still abound about how many exactly have died, what caused the fire, what the building’s history is, whether the party’s attendance exceeded its maximum occupancy and whether there had been any code violations in the past. Arson investigators also will be at the scene of the fire.

“We’re not going to find those answers right now,” Watson told reporters. “We’re very much focused on identifying all those who are still missing.”

The majority of those inside the building are young people, some of whom are from outside the Bay Area, Officer Kelly told reporters. Some are foreigners.

“Last night’s fire was an immense tragedy. I am grateful to our first responders for their efforts to deal with this deadly fire,” Oakland Mayor Libby Schaaf said in a statement. “Our focus right now is on the victims and their families and ensuring that we have a full accounting for everyone who was impacted by this tragedy.”

The event’s Facebook page is now filled with people inquiring if their loved ones have been accounted for. Some asked how they can help.

A list of people who were missing has been created in a Google docs spreadsheet, along with any identifying features and their loved ones’ contact numbers. About 40 names are listed on the spreadsheet as of Saturday afternoon; seven of whom have been deemed either safe or in the hospital.

Deloach-Reed said fire officials will verify those names against the ones they have.

“This is pretty tragic for us,” Deloach-Reed said. “It is hitting this community pretty hard. I don’t even want to talk about how the families and friends are feeling. We have a community that’s hurting.”

A total of 72 firefighters responded to the fire, Deloach-Reed said. Crews had to fight the blaze from outside because it was too hot and too intense for firefighters to go inside the building, she said.

Battalion Chief Lisa Baker said three sides of the building were on fire, the San Jose Mercury News reported.

Deloach-Reed told the East Bay Times that most of the nine people who were killed were found on the second floor of the building. She told The Post that the warehouse used to have one floor, but a makeshift ladder and another floor had been added.

A large blaze and thick smoke was seen coming from the building at about 3 a.m. Saturday.

Kelly told reporters that the structure’s roof had collapsed, and the building has so far been deemed unsafe for fire crews, who are determining how to inside the building. Officials will be sending out drones to assess the building and surrounding areas, according to news reports.

“There’s still a large portion of the building that we’re going to have to search,” Deloach-Reed said.

The warehouse had been partitioned into several artist studios and was packed with furniture, mannequins, lamps and other objects, according to the Associated Press. Fire officials said the building did not have sprinklers.

Watson, of the Oakland Police Department, said investigators have talked to people who either left the building before the fire broke out, or were able to escape. She declined to share further details.

Deloach-Reed said this is the worst fire the city has seen since the Oakland hills firestorm that killed 25 people in 1991. That fire, which rapidly spread through the Oakland hills wiped out nearly 3,500 homes, according to the San Francisco Chronicle.