REDWOOD CITY -- A six-alarm fire sent flames shooting up into the predawn sky and destroyed a large metal fabrication business Friday.

The fire on Douglas Avenue, visible from Highway 101, displaced about 15 people living in an apartment complex next door, according to Redwood City fire Marshal Jim Palisi.

All of the residents safely evacuated and there were no reported injuries.

The Red Cross was helping the displaced residents.

The Bay Area Air Quality Management District responded to the scene as smoke and a foul-smelling odor permeated the surrounding neighborhood.

"Smoke is dangerous, it doesn't matter what kind it is," Palisi said. "But we're doing what's necessary for our community."

The Redwood City Fire Department later reported there was no health hazard but suggested people experiencing heavy smoke in the neighborhood stay indoors.

Palisi said the fire originated in the machine shop and extended to the apartment complex. A tool company located next door to the machine shop appears to have avoided any fire damage.

The machine shop was empty when the fire started.

The cause of the blaze is under investigation.

Terry Bowman, manager of the tool company located net door, stood across the street Friday morning as firefighters continued to battle the blaze. He was anxious to get inside and assess the damage.

Palisi said a fire wall separating the two businesses kept flames from spreading.