Firefighters were close to controlling a six-alarm fire at a machine shop in Redwood City late Friday morning, but not before it spread to an adjacent apartment building and displaced more than a dozen residents, a Redwood City fire marshal said.
Firefighters responded at about 5:50 a.m. to the blaze at 894 Douglas Ave., according to a San Mateo County fire dispatcher.
FMW Machine Shop is located at that address.
Firefighters had contained the fire as of about 9:15 a.m. but had not declared it under control, Fire Marshal Jim Palisi said.
Before firefighters could contain the massive blaze, it spread to a nearby apartment building, causing "significant" damage, Palisi said.
About 15 people live in the building and won't be able to return Friday, he said.
Damage to the machine shop was extensive, including the collapse of the building's roof, Palisi said.
According to county officials, the response to the fire has prompted the closure of nearby streets.
Broadway is closed in the area and Spring Street is also closed between Sweeney and Hurlingame avenues, county officials said.
The San Mateo County Health System is advising residents to stay indoors to avoid exposure if they smell smoke. The agency warns that children, the elderly and people with respiratory conditions are particularly sensitive, spokeswoman Robin Thaw said.
Other steps to mitigate risks from smoke inhalation include setting air conditioning units and car ventilation systems to re-circulate air, Thaw said.