A San Francisco firefighter suffered minor injuries while battling a huge, five-alarm blaze at the edge of the Mission District Tuesday morning.

The fire, visible from many parts of the city, potentially began at or near a building supply warehouse on 14th Street, fueling the flames with a large amount of lumber and other flammable materials. It was reported around 7 a.m., and by 10 a.m. firefighters had largely contained with the help of some 100 million gallons of water, as the Chronicle reports.

The SFFD was reportedly helped by the Water Department after exhausting the water supply in all nearby hydrants as they fought the fire. As KPIX reports, firefighters ended up tapping the city's water reserves to prevent the spread of the flames.

"We used our Jones Street tank and we went up to our Ashbury Street tank and now we are flowing water all the way from Twin Peaks," said deputy fire chief Victor Wyrsch, speaking to KPIX.

Fighting the fire also involved the complication of falling transformers and power lines, and PG&E reportedly got power turned off to the area quickly.

One firefighter "got knocked in the head a little bit," as Wyrsch tells the Chronicle, and he was hospitalized out of "an abundance of caution."

The fire caused damage to as many as six commercial buildings on the block that is bounded by 14th Street, Erie Street, Folsom Street, and South Van Ness Avenue, and has reportedly displaced at least 100 workers from their jobs.

One of the buildings threatened and/or damaged was occupied by the San Francisco Sheriff's Department, and KPIX reports that it had a basement full of live ammunition.

Smoke from the fire blew toward the East Bay and remnants are expected to linger in the air for hours. As a result, the Bay Area Air Quality Management District issued a warning to residents with breathing issues to remain indoors with windows closed for the rest of today.

Bartfeld Sales, a the building supply company, is a 73-year-old family-owned business that was completely destroyed by the fire. Family member and co-owner Brian Bartfeld told KTVU that his father had arrived at work before sunrise this morning and the building was already fully on fire. "The whole building is gone," he said.

Bartfeld added that he was glad that no one was hurt or killed in the fire.

The cause of the fire is under investigation.

Earlier: Five-Alarm Fire Burns Multiple Commercial Buildings in Mission Next To 101 Overpass

Photo: Andrew Warren