Cal OSHA said the fire department violated its own procedures which may have led to fatal mistakes six months ago.
Lieutenant Vincent Perez and firefighter Anthony Valerio of Engine 26 perished in that tragic fire.
The blaze broke out in the early morning of June 2 at the multi-level house that hugs a hillside.
The two firefighters went through the front door and reported that it appeared to be a small fire, but as they proceeded down to the lower floors, the flames exploded, ultimately killing both of them.
Cal OSHA issued four citations -- three of them categorized as serious -- and said personnel located outside the house did not maintain communications with the two crewmembers of Engine 26.
A battalion chief entered the house by himself without maintaining visual or voice contact with any other employee inside the house.
Finally, the department did not ensure that at least two firefighters outside were assigned to perform assistance or rescue activities.
Cal OSHA says the procedures they cited may have saved lives.
"It would have really created an environment where all involved would have known exactly where the hazards were, what was going on at any given time, and it could have resulted in a different response," said Cal OSHA spokesman Dean Fryer.
The fire department says it will appeal all the citations.
"We have documentation to prove that these citations are not based on what we think happened up there," said Asst. Dept. Chief Jose Velo.
Velo said the fire crew had backup personnel and that the battalion chief did talk to Perez and Valerio in the house. Velo said they had radio communications, which somehow failed during the fire.
The firefighter's union says it's more concerned about the internal fire department probe than with Cal OSHA's investigation.
"They have the documentation of the radio transcripts, with the times of each radio transmission was made," said Tom O'Connor with the San Francisco Firefighter's Union. "You have video footage from neighbors with time stamps on the bottom, so you can track the radio transmissions with growing fire."
Cal OSHA has imposed a fine of $21,000. That fine and the citations will be contested.
The SFFD's own investigation is almost done and the report could be released within the month.