The fire was an accident and the homeowners feel terrible that something they did led to the fire. There is great relief that this fire wasn't set by someone on purpose.
The fire was huge. It started at 3 in the morning and spread to the building next door. A total of six people had to make a quick escape.
"We heard the crackling of the fire. So then we got very nervous. You try to think of what to take and of course I didn't take the pictures," said fire victim Lois de Buren.
The homes are located on Clayton Street in Lower Twin Peaks, just across Market Street from the Castro. And of course the recent arson fires that have hit the Castro were on people's minds.
"It is within close proximity to the fires last week that we determined to intentionally set. So we are fully aware of that. So it's premature to state whether this was set intentionally," said SF Fire Chief Joanne Hayes White.
There were four fires in the Castro District on Thursday and Friday. Firefighters believe an arsonist is responsible for at least three of them. But the residents on Clayton Street had their doubts that the firebug had made it to their neighborhood. They instead focused on the new deck the residents had been working on.
"It started on their deck in the back, and I really don't think it was anyone from the Castro District that would be doing that. I could be wrong, but I really think it was just an accident," said resident Steve Kulvirenti.
"My guess is when they stained it or something, it doesn't take a hell of a lot. If you leave a chemical rag it can combust," said Buren.
It turns out - they were exactly right. Arson investigators said the fire started because of the work being done on the deck.
"They had been using some stain and the rags that they had been using spontaneously combusted," said SF Fire Dept. Spokesperson Mindy Talmadge.
"I am so glad to hear that. I didn't think so. I thought it had something to do with maybe the construction going on, but it is very good to hear that," said resident Chris Jones.
Firefighters said to prevent this kind of fire, you can put your rags in a bucket of water when you are done with them.