Federal investigators from the Bureau of Alcohol, Tobacco and Firearms are focusing on electrical issues, possibly an overloaded circuit, as they look to pinpoint a cause for the fire that killed dozens of people during a dance party in an Oakland warehouse.
Flames ripped through the so-called Ghost Ship warehouse on Dec. 2, killing 36 people. The blaze is the country's deadliest building fire in more than 13 years.
First responders on Monday returned to the warehouse, where they marched together before holding a moment of silence to remember and honor the victims.
A bell tolled 36 times, once for each victim.
"It does provide closure to just realize that we were all a part of this; it was no one person," said Ed Moore, chaplain with the Alameda County Sheriff's Office.
The Ghost Ship was one of many Oakland warehouses converted to work and living havens for musicians and artists. The communal living spaces have helped nurture a thriving underground art scene and provide space at a reasonable price in an area where astronomical rent hikes fueled by the tech boom have driven many people out.
Some of those artists also were trying to heal Monday night across town at the Flight Deck, an artists space on Broadway. There, they held a story circle.
"The way your creative practice helps you process pain or helps you heal, it was really about each other listening," said Katherin Tanton, of Arts for a Better Bay Area.
Some are crying out for more affordable housing in the Bay Area to prevent another tragedy like the deadly warehouse fire. The issue is scheduled to be discussed late Monday at the Oakland Tenants Union meeting.
Federal officials will hold a news conference Tuesday to provide updates on the investigation.
NBC Bay Area's Terry McSweeney and the Associated Press contributed to this report.