More than two dozen residents were displaced by a fire that damaged an apartment building in Redwood City Wednesday morning, a fire official said.

Firefighters responded to multiple reports of smoke and fire at a two-story, five-unit apartment building in the 400 block of Alden Street at about 4:20 a.m., Redwood City Fire Department spokesman Dave Pucci said.

An apparent electrical malfunction sparked a fire that spread up the exterior of the building and into an attic space above the apartments, Pucci said.

No one was injured in the blaze, which was brought under control in just more than two hours.

The apartment building was rendered uninhabitable, and 29 people were displaced, according to the American Red Cross Bay Area Chapter.

The Red Cross opened an evacuation center for the fire victims at 1400 Roosevelt Ave. in Redwood City, spokeswoman Cynthia Shaw said.

Anyone who needs assistance with temporary housing or food should go to the evacuation center or call (888) 4-HELP-BAY.

The one-alarm fire caused an estimated $600,000 in damage to the structure of the building, and $100,000 in damage to its contents, according to the fire department.

The cause of the fire remains under investigation, though preliminary information indicates it was accidental.

The incident underscored the importance of maintaining functioning smoke detectors, especially in multi-unit apartment buildings, Pucci said.