A fire of unknown origin damaged an East County apartment building Monday afternoon, displacing four families and causing an estimated $300,000 in damage.

The non-injury blaze in the 300 block of West Park Avenue in El Cajon erupted shortly after 3 p.m., Heartland Fire & Rescue spokeswoman Monica Zech said.

It took crews from several area agencies about 40 minutes to fully extinguish the flames, which destroyed two dwelling units and damaged a third.

The American Red Cross was called in to help the affected residents arrange for interim lodging, Zech said.

The cause of the fire was under investigation.

— City News Service