OAKLAND, Calif. >> The converted warehouse known as the “Ghost Ship” where a deadly fire ripped through a late-night dance party was an artist workspace and illegal home for a rotating cast of a dozen or more residents, those who lived there or visited often said.

Former residents said it was also a death trap with few exits, a rickety makeshift staircase, piles of driftwood and a labyrinth of electrical cords. The ground floor had five recreational vehicles and other nooks used as living spaces that were rented out to tenants, while the upstairs had space for concerts like the deadly party that drew up to 100 people Friday night.

With few lights, the place could be pitch black. One staircase led to a boarded up door. The water and electricity were stolen from neighbors and often didn’t work.

“If you were not familiar with the building and the way that it was, if you were going there for a party, you wouldn’t be aware of the maze that you have to go through to get out,” said Danielle Boudreaux, a former friend of the couple who ran the warehouse.

Firefighters pulled nine bodies from the charred rubble of the building Saturday and set up massive spotlights to continue a search they said would last at least 48 hours. They estimated at least two dozen remained missing.

Boudreaux identified the operators of the collective as Derick Ion Almena and Micah Allison. She said she had a falling out with Almena when she persuaded Allison’s parents and sister about a year ago that the warehouse was a dangerous place for the couple’s three children to live.

The couple charged tenants enough to cover the warehouse rent and used proceeds from parties to pay their own living expenses, Boudreaux said.

On Saturday, the artist retreat had turned into a scene of horrors, the 4,000-square-foot structure charred to rubble. The building’s roof had collapsed into the second floor, which in places fell to the bottom floor. Firefighters had to temporarily stop their search and rescue operations Saturday when they became too dangerous, taking time to shore up the structure, Oakland deputy fire chief Mark Hoffmann said.

Oakland officials said they had opened an investigation just last month into the warehouse after repeated complaints from neighbors who said trash was piling up and people were illegally living in the building, which was zoned as a warehouse.

Darin Ranelletti, of the Oakland Planning Department, said the city opened an investigation Nov. 13 and an investigator went to the premises on Nov. 17 but could not get inside. The city has not confirmed people were living inside.

Shelley Mack said she lived there about two years ago, staying four or five months. She said she wasn’t told the residence was illegal until after she moved in, when she was instructed to tell visitors it was a 24-hour workspace for artists.

When outsiders or inspectors planned to visit, residents would scurry to hide clothes and bedding, Mack said.

“It’s like a horror house. Just horrors in there,” she said, referring to things such as no electricity, running water and freezing temperatures.

Alastair Boone, 22, a University of California, Berkeley student arrived at the party with five friends around 11 p.m. and had just received a tour of the property and stepped outside before the fire broke out.

“In a couple of minutes there were flames coming out of the windows and black smoke was just billowing out of the house,” she said.

A man identified as Derick Ion posted a Facebook message early Saturday, saying “Everything I worked so hard for is gone. Blessed that my children and Micah were at a hotel safe and sound.” He drew rebukes online from others who said he was warned the building was unsafe.

Almena did not immediately respond to emails sent to addresses affiliated with him. Phone numbers either rang continually or were disconnected. Authorities declined to talk about the manager when asked by reporters Saturday, saying they were focused on recovering the bodies and consoling the families.

Online records listed the building’s owner as Nar Siu Chor. The Associated Press could not locate a telephone number for her Saturday and efforts to reach her at other Oakland addresses associated with her were not successful.

A website for the warehouse showed pictures of a Bohemian, loft-like interior made of wood and cluttered with rugs, old sofas and a garage-sale like collection of pianos, paintings, turntables, statues and other items. Advertisements touted various electronic music parties. Friday night’s event featured musician Golden Donna’s 100% Silk West Coast tour.

It’s unclear what sparked the fire, but officials said the clutter served as a tinderbox and there were no sprinklers inside.

Alameda County Sheriff’s Sgt. Ray Kelly said people either escaped from the building or died inside, where the only way down from the second story was via a stairwell constructed entirely of wooden pallets. “It appears that either you got out or you got trapped inside.”

About 50 to 100 people were believed to have been at the party when the fire started around 11:30 p.m. Friday, officials said.

“We know there are bodies in there that we can’t get to — that have been seen but not recovered,” Kelly said.

Monica Kat, a paralegal, feared four of her friends were dead.

“We we were all checking in looking for them and they’re still not accounted for and I can only think the worst at this point,” she said.

Dan Vega had been unable to find his 22-year-old brother or his brother’s girlfriend.

“I just want to go over there. I have my work boots on. I’m ready to go,” Dan Vega said.

Oakland police urged those concerned about missing people to call the Alameda County Sheriff’s Coroner’s Bureau at 510-382-3000.