The warehouse, known as the Ghost Ship, has a long history of holding parties. Several high-tech DJs were performing Friday night.
The event was set to continue until 4 a.m., but the fire broke out just after 11 p.m.
On Nov. 14, a blight complaint was filed saying the property was piling up with tons of garbage, where items were left on the sidewalk near the property -- with some trash deemed hazardous. The owner of the property said it's a storage space. However, it was submitted as a trash recycle site.
The warehouse's main building turned into a residential site for the artist community, where individuals were living inside the cramped space. Photos revealed the inside living conditions of the warehouse and of the artists' set-ups.
A Housing Habitability complaint is issued on the site with the pending investigation. The complaint states the site has "illegal interior building structures." Complaints date back over a year regarding the cramped conditions, electrical wiring issues, people living there and more.
KGO-TV spoke to an official briefed on the situation, who said early indications show that the blaze was not arson but appears to be an electrical fire. Those details were not yet confirmed.
Officials told KGO-TV the only sole exit was blocked by the fire and that once the fire started, the power went out. People became disoriented inside which made it difficult to escape the flames. The fire chief explained pallets were stacked up as makeshift stairways.
Investigators were working to determine if code enforcement was aware the building was being used as entertainment.
It appears the owner of the property was cited several times for blight and there was an ongoing investigation about inappropriate building inside the property.
There were no citations on having parties at the site, but citations on the property were regarding people living there, wiring issues and more. The property is valued $43,294.
Officials said criminal charges were possible depending on the investigation outcome.
Click here to find out if people in the area are safe.
Click here to donate and help the the families of the victims. The fund had raised about $40,000 out of its goal of $100,000 as of 3:30 p.m.
Bay City News contributed to this story.