A historic gas station-turned-office building in Southtown was severely damaged by a fire on Friday.

The San Antonio Fire Department sent more than 100 firefighters to the 1500 block of South Flores Street just after 10 a.m. At 12:45 p.m. Friday, fire department spokesman Joe Arrington said the bulk of the fire had been put out and first responders were now tamping down hot spots around the site. No one was injured in the blaze, and investigators were working to determine its cause.

“It’s wrapping up,” Arrington said early Friday afternoon. “Both of the main structures on that triangle-shaped [parcel] were heavily damaged.”

The triangle-shaped building, which sits on a triangular parcel of land between Nogalitos and South Flores Streets, is known as the “Historic Site Triangle Garage” on the Office of Historic Preservation’s interactive map of historic landmarks. It was built in 1929, and currently houses web design and creative firm Sweb Development.

Vince Michael, executive director of the Conservation Society of San Antonio, said the building was included in the preservation organization’s ongoing survey of gas stations around the city. That particular former gas station had been surveyed around 2011, he said.

It’s a 1929 Spanish-eclectic Mission-style gas station,” Michael said. “It had been converted into offices some time ago.”

He said he was astonished by how “ferociously” the fire burned at the site. He mourned the potential loss of the building, but acknowledged that San Antonio has lost historic structures to fires before.

“That’s a very key intersection, where Nogalitos [Street] is splitting off from Flores [Street],” Michael said. “It’s unfortunate if we lose that building, and it’s surrounded by other lovely buildings.”

The building behind Sweb, which appeared to be a commercial-residential combination, also was damaged. Arrington said it appears that the fire started in the alleyway between the two structures and spread from there.

“Arson investigators are on scene to make an official determination of where it started, but they do know it started outside,” Arrington said.

Inspectors from the City of San Antonio’s Development Services Department will visit the site and decide what to do with the structure, but it will most likely be torn down, Arrington said.

“It was very fortunate that everyone evacuated safely,” he said.

Jackie Wang covered local government for the San Antonio Report.