OAKLAND, CALIFORNIA (REUTERS) - The two-story warehouse engulfed by a deadly Oakland fire at a Friday (Dec 2) night dance party was typical of the collective spaces artists and musicians say they have increasingly looked for to cope with rising rents.

The cause of the fire remains under investigation, and a city building official told a news conference the building was most recently zoned as a warehouse. It was not approved as living space and had no concert permit.

The fire killed at least nine people and left about two dozen missing, raising fears the death toll would rise.

Property records list the owner as Chor N. Ng and that he purchased the warehouse in 1997. He also owns other properties in the city, the Daily Mail reported.

Oakland City Councilman Noel Gallo, who lives a block from where the fire occurred, told the San Francisco Chronicle that the building "has been an issue for a number of years".

"People have been living inside, and the neighbours have complained about it,"he said.

"Some of these young people that were in there were underage. They frequently had parties there."

But officials have not confirmed whether people were living in the building, which had first floor spaces divided by home-made partitions and a staircase to a second level fashioned with wooden pallets.

However, high rents have forced many artists and musicians to overcrowd houses, take such accommodations and hold concerts and open houses to make ends meet, members of the artistic community said. They are also reluctant to ask landlords to bring living quarters up to fire code standards for fear of eviction.

"If you have multiple roommates (in a house), it is still US$1,000 a month," said rock musician Courtney Castleman, 33, who left Oakland for nearby El Cerrito because of unaffordable rents.

Renting a space in an Oakland warehouse, by comparison, could cost US$600 (S$850) to US$700 per month, she said.

Castleman was one of several musicians on Saturday who said Oakland - a city of 400,000 across the bay from San Francisco - needs more affordable housing and rent control to help artists live and stay safe.

"I do know other warehouses in Oakland in similar condition," Castleman said. "You don't necessarily trust the landlords to do the work they are supposed to do because they will evict you."

People who had been inside the warehouse described the building as full of pianos and sculptures with rooms where artists lived and worked.

Firefighters could be seen on video afterward hauling out an upright piano near the entrance.

"It's beautiful inside - Disneyland meets Tiki Room," said a 35-year-old woman who said she goes by the name Lisa Aurora.

City officials in November received complaints about debris outside the building and launched an investigation into whether people were living inside.

"The whole place was built like you are going to set up for a fire," said Matt Hummel, 46, who has worked in construction and helped renovate other warehouse spaces for artists.

Hummel said the building had bedrooms and workspace and the uneven stairs to the second floor were like "climbing a fort."

"It's like a big house, except you have an event some days to help pay the rent," Hummel said.