EAST PALO ALTO (BCN) — A two-alarm fire at an apartment complex in East Palo Alto displaced 21 residents Thursday, firefighters said.

The Menlo Park Fire Protection District responded around 11 a.m. to the Royal Oaks Apartment Complex at 1928 Cooley Avenue on a report of a fire.

The fire broke out in a unit on the third floor of the three-story, 70-unit building.

Firefighters were able to bring the fire under control in about 20 minutes.

The apartment where the fire started sustained fire damage, two units sustained water damage and one sustained smoke damage, firefighters said.

The unit where the fire broke out was not occupied when the blaze started, and there were no reported injuries.

Of the 21 residents displaced by the fire, 12 were adults and nine were children.

Investigators determined the fire started in the living room of one of the units and was likely caused by a faulty extension cord, firefighters said.

The fire did an estimated $70,000 in damage to the structure, and about $12,500 worth of contents was lost in the blaze, firefighters said.

The displaced residents were relocated to other apartments in the complex.