Lists of the missing circulated, as many living in the Bay Area took to Facebook to mark themselves as "safe," or to check on the status of a friend. Many of those who had been unable to reach friends in the past two days had given up hope when authorities said people either escaped without injury or died inside.

Authorities would not answer questions about the couple that operated the Satya Yuga collective. They were identified as Derick Ion Almena and Micah Allison. Both were believed to have been out of the building at the time of the blaze.

Almena had leased the space from its owner and then rented five recreational vehicles and other nooks on the ground floor as living spaces, said Danielle Boudreaux, a former friend of Almena and Allison. They held regular concerts and dance parties, like the one Friday, to make money, Boudreaux said.

Shelley Mack was drawn there by the promise of living among artists and paying a reasonable rent in an area where the tech boom has created a housing shortage and exorbitant leases. She left after a few months, two years ago, when the place failed to live up to its promises.

"Some people were happy to have a roof over their head even though there was no heat or no place to eat, or that it was filthy and infested," Mack said. "You just get sucked in because it seems like it's this nice place and this artistic community and they talk a good game. There are people there that wanted to be there and believed in it. And I think I did, too, for a little bit. And then…afterward, I was like, um no."