O'Brien was joined at a news conference Thursday by the families of Lt. Robert Neary and Daniel Sweeney, the two firefighters killed, as well as by Joseph Schulle, president of Local 22 of the firefighters' union.
"The reality . . . is this incident could happen again tomorrow," Schulle said.
Fire Commissioner Lloyd Ayers said that engine companies conduct constant block inspections for "target hazards," and that building data from the Department of Licenses and Inspections are available on the fire dispatch computer system - one upgrade since the Kensington blaze.
An L&I spokeswoman also noted that inspectors were in the midst of cataloging, inspecting, and citing the city's vacant private properties - nearly 13,000 have been visited so far.
Ayers said the department also had conducted training on the findings of federal investigators who looked at the Kensington fire as well as a similar tragedy in Chicago.
"We lost two members. . . . We have firefighters still hurting from that. My heart still hurts," he said. "We're going to learn from this and the firefighters are going to do what they have to do to move forward."
After the fire, the District Attorney's Office impaneled a grand jury to investigate. O'Brien said he believed a report was imminent.
"I predict that will be a blistering report that also calls for immediate action," he said.
Firefighters battled the five-alarm blaze mostly from the perimeter. Neary, Sweeney, and two other firefighters were trapped by the collapse in an adjacent store about 30 minutes after the fire was declared under control.
Councilman criticizes city on the hazards of vacant buildings. B4.