A fire at a Bayview warehouse has prompted a shelter-in-place, officials say, and has sent clouds of smoke into the San Francisco skies.

The San Francisco Fire department first announced the fire at 1300 Donner Avenue at 1:11 p.m. Friday. Matters quickly escalated, as SFFD then tweeted at 1:31 "AVOID AREA WE HAVE MANY HAZARDS ASSOCIATED TO THIS FIRE."

By 2:19 p.m., the blaze was declared a four-alarm fire. According to SFFD spokesperson Lt. Jonathan Baxter, as of 3 p.m. there are 122 firefighters and 40 apparatus at the scene "to keep the fire from spreading."

It's around then that residents of the area near Third Street and Carroll Ave were ordered to shelter in place, and were told to "stay inside and close windows to reduce exposure to smoke."

1300 Donner Avenue is the location of what was once the United Brass Foundry. Since then, that business has shuttered, as fire officials say the burning structure "is a vacant metal shop."

As of 2:58 p.m., the SFFD says that "so far we have kept this to 1300 Donner Ave with no exposures no injuries and no displaced." According to the Chron, "rescue teams have done multiple sweeps of the building, but have found no one inside."

"There were electrical wires sparking and firefighters were concerned about the integrity of the warehouse’s walls," the Chron reports.

“There’s a lot of toxic materials inside,” SFFD chief Joanne Hayes-White said.