The devastating fire that destroyed several buildings on Mission Street near 29th St. and left 56 people homeless last June was most likely caused by smoking or unsafe BBQ charcoal disposal. That’s the conclusion of the San Francisco Fire Department’s investigation into the June 18 blaze, which apparently started of the roof of 3316 Mission St., the building that housed Cole Hardware store.

KQED reports:

After the fire was subdued, investigators encountered extensive damage: floors, ceilings and hallways collapsed; a roof on one building that had been completely consumed by flames; and windows that had blown out because of the intense heat.

The first clues of a potential cause came from an unidentified woman living in one of the residential units. She told investigators she saw smoke and flames coming from an area where there were two plastic trash receptacles. She said she occasionally saw a neighbor smoke on the adjoining balcony. She stated “sometimes he uses an ashtray and sometimes he does not,” the report said.

Two unidentified Cole Hardware employees told investigators that they saw smoke and fire coming from trash receptacles on the roof. One of them said “the ‘whole trash can’ was on fire,” according to the report.

Investigators found the melted remains of one trash receptacle they say had burned into the roof. Another receptacle was also severely damaged by heat and fire. It was in that area officials believe the fire began.

“In this immediate area we located the remains of burnt combustible materials,” the report stated. “In the area we also located the remains of discarded smoking materials.”

Investigators also believe that “improperly discarded smoldering barbecue charcoals” could have been placed in the trash receptacles.

Here’s an aerial view of the same scene as it looked before the fire, as archived by Apple Maps. Notably, two plastic trash bins are visible on a deck above the ground-floor Cole Hardware store, though it’s unknown if these were the same ones where the fire originated:

UPDATE: Wow. Back in January 2015 when he visited 3316 Mission Street as part of his historical research into the Catto family’s connection to the building, Neighbor Michael Nolan took some close-up photos on the small deck off the upstairs apartments above Cole Hardware. As fate would have it, he also photographed the trash bins on the deck too. Here’s a close-up from January, 2015, shared with us today. This is the spot where the fire may have started:

2015 photo of trash bin on the rear deck of 3316 Mission, courtesy of Michael Nolan

Notice the text on the trash can lid? “No Hot Ashes.” Ugh.

Meanwhile, the KQED article also contains a sad footnote, to the effect that Cole Hardware is unlikely to make a permanent return to Bernal’s stretch of Mission Street.

However, all hope may not be lost. Cole Hardware will operate a local pop-up shop on Mission near its old location during this holiday season, and Cole Hardware co-owner Rick Karp says:

[Cole Hardware is] opening a temporary holiday pop-up shop at the intersection of 29th and Mission. It’s next door to Pizza Hacker. We will be open Fridays, Saturdays and Sundays from Thanksgiving until Christmas. We’ll have Christmas trees, both cut and live, garland, poinsettias, lights, gift wrap, lots of decor and more!

Please come by and say hello, have some wine or cider, and do some holiday shopping too. Former Mission store staff members Jose, Shanead and Jonathan will be running the show.

We are so sad not to be a part of the neighborhood anymore. We continue to watch for vacancies that could be a new home for us. No luck thus far, but we are hopeful. The landlord of the previous store has sold the property. We will be doing whatever we can to lease the retail space in the new building. We’ll keep you posted.

PHOTO: Top, annotated aerial view of the Cole Hardware fire site, as captured via drone in late June, 2016 by Alan Musselman.