Investigators cannot determine cause in Oakland construction fire

Firefighters battle a building fire at Valdez and 23rd streets in Oakland on July 7. Firefighters battle a building fire at Valdez and 23rd streets in Oakland on July 7. Photo: Noah Berger, Special To The Chronicle Photo: Noah Berger, Special To The Chronicle Image 1 of / 44 Caption Close Investigators cannot determine cause in Oakland construction fire 1 / 44 Back to Gallery

The cause of a fire that demolished an under-construction complex in Oakland last month cannot be determined, federal investigators said Friday, leaving open the question at the center of a battle over development and displacement in the city.

Immediately after the July 7 blaze, speculation grew that an arsonist was out to burn East Bay developments with the goal of combatting gentrification. The announcement Friday did little to relieve fears among developers, who have been working to enhance security measures at project sites.

“People were concerned, ‘Was this a pattern?’” said Councilwoman Lynette Gibson McElhaney, who represents the area that includes Auto Row, the site of the seven-story Alta Waverly mixed-use building on Valdez Street that was destroyed. “People are about mitigating risk. They wanted to know what would be the determination of the source of the fire.”

“While the investigation has reached a point where an ‘undetermined’ finding is appropriate, investigators will continue to consider any new evidence or information provided by witnesses or community members,” the Bureau of Alcohol, Tobacco, Firearms and Explosives said in a statement.

Steve Carman, a private fire investigator in Grass Valley, said the conclusion of “undetermined” was typical. During his two decades working for the ATF, he said, about a third of his cases turned out that way.

“Unless you can eliminate all but one hypothesis, you really don’t have a single conclusion that can stand by itself,” he said. “That doesn’t necessarily means it’s the end of the investigation. You can go back and gather more evidence and data, perhaps do more testing, look for more witnesses.”

In a situation where multiple stories collapsed onto one another, the entire building was scorched and no witnesses came forward, finding a cause would be extremely difficult, Carman said.

The fire was a major setback for the city’s plan to redevelop Auto Row. No one was injured, but hundreds of nearby residents — including Oakland’s new police chief — were temporarily displaced.

Twenty-eight people living in two adjacent buildings, including a couple with a 2-year-old child, haven’t been able to get back into their homes since the fire, according to Michele Byrd, the city’s director of Housing and Community Development. Wood Partners, the Alta Waverly site developer, has paid for their stays at a Jack London Square-area hotel, she said.

In one case, scaffolding that fell from the construction site damaged an apartment’s roof. In the other, investigators checking to make sure the units were safe for re-entry found unrelated code violations, said city spokesman Sean Maher.

The building that was going to comprise nearly 200 housing units and 31,000 square feet of retail space was more than halfway done at the time of the fire. It would have been the largest project in Oakland’s Broadway Valdez District, an area city officials want to turn into a pedestrian- and bike-friendly housing and retail zone.

Wood Partners has vowed to begin construction again, with a new completion date projected for the beginning of 2019.

The Valdez Street fire came less than two months after an arson destroyed a housing development on San Pablo Avenue in Emeryville near the Oakland border. It was the second suspicious blaze at the project and prompted its developer, Rich Holliday, to say the three fires together amounted to a “war on housing.”

Councilman Abel Guillén suggested someone had deliberately set the Valdez fire, tweeting that morning, “Burning down housing doesn’t help make #Oak housing more affordable. It only speeds up displacement of existing residents.”

Amid concern that builders would halt plans in Oakland, Mayor Libby Schaaf reached out to developers to assure them that the city would work with them to shore up safety measures at their project sites, said Darin Ranelletti, interim director of Oakland’s Planning and Building Department.

With about 3,000 housing units under construction, Ranelletti said there’s “still tremendous interest in development.” The city hasn’t seen a slowdown of project proposals or anyone pulling out, he said.

But developers throughout the city have increased lighting at construction sites, added surveillance cameras, hired guards and taken other steps to secure perimeters, Ranelletti said. .

The ATF said that anyone with information on the fire could leave confidential tips at (888) 283-3473 or on www.reportit.com.

Kimberly Veklerov is a San Francisco Chronicle staff writer. Email: kveklerov@sfchronicle.com Twitter: @kveklerov