A fire that erupted during a dance party at a warehouse used by an artists' collective in Oakland, California, has killed at least nine and about two dozen people are missing, raising fears that more bodies will be found inside.
City and Alameda County officials said they expected the death toll to climb once the burned-out ruins of the two-story building were shored up and recovery teams were able to safely enter the structure.
The blaze started at about 11:30pm on Friday in the city's Fruitvale district, a mostly Latino area that is also home to many artists living and working in converted lofts.
The cause of the blaze and exact number of casualties remained undetermined, said Oakland Fire Chief Teresa Deloach Reed, who called it the worst single-structure fire she had seen in her career.
Nine fatalities had been confirmed, and authorities were working to account for "a couple of dozen" other people and were "expecting the worst", Sergeant Ray Kelly, a spokesman for the county sheriff, told a news conference.
The remains of only one of the nine confirmed dead had been recovered as of Saturday because the warehouse was still too unstable to enter, said Deputy Fire Chief Mark Hoffmann.
He said about a dozen people survived the blaze, including one individual who went to a local hospital for treatment. The party was taking place on the second floor of the building, which had just two exits, at the time the blaze began, officials said.
The warehouse roof collapsed onto the second floor of the building during the fire, according to authorities, and portions of the second floor caved in on the first story.
Authorities said they did not suspect arson, but investigators want to find out if the building, which was partitioned into artists' studios, had a history of building code violations.
The city's buildings and planning chief, Darin Ranelletti said there were reports that people were living there, but no permits had been issued for habitation. It was unclear, he said, whether special permits would be needed for the artists who had set up shop inside.
Many of the victims were young people in their 20s or 30s, authorities said.
Authorities have said they did not know how many people were at the party or how many lived on the premises.
A Facebook event page showed 176 people planned to attend the party, which featured electronic music performances.