The inferno erupted at a complex under construction in San Francisco's Mission Bay neighborhood. And, this afternoon, a city commission heard the latest in the investigation.
The fire was described as a difficult one for firefighters.
"There was no sheetrock in place, there was no sprinkler systems in place; nor fire alarm systems. There was no protection systems to prevent the spread of the fire," said Assistant Fire Chief Bob Postel.
Postel updated the Community Investment and Infrastructure Commissioners at City Hall.
According to the investigation, workers had left the building about an hour before the fire started. There are reports that workers had been using welding torches.
"The cause is still under investigation and I have no time frame on when they'll have a cause on that," said Postel.
The city's project manager for Mission Bay was also at the hearing. Catherine Reilly told them the demolition of that building will be finished in about four to six weeks.
Then, the reconstruction could begin shortly after.
"I would guess once it's cleared off and they've got ready to go, maybe a year if not quicker, if they can salvage the concrete," said Reilly.
Two other buildings across the street from the fire suffered some damage. Fifty-four units are still inhabitable.
"A lot of smoke damage, broken windows and then some of, some water damage to our walls because of the sprinklers," said resident Meghan Moxley.
Moxley was able to transfer her lease to the adjacent building. It will be several weeks before clean-up crews finish work inside the affected units.