CHULA VISTA, Calif. — Four firefighters are recovering from injuries they suffered battling a three-alarm fire at a Chula Vista retail store.

The blaze was reported at about 5:40 p.m. Monday at Action Footwear, 655 H Street, just east of Interstate 5, according to the Chula Vista Fire Department.

Investigators believe the fire started on the second floor and was driven by high winds. A second alarm was called shortly after crews arrived and was upgraded to a third alarm when the roof collapsed.

Four employees who were inside the building when the fire started reportedly escaped unharmed.

Three firefighters were taken to UC San Diego Medical Center -- one for treatment of second-degree burns who will stay in the hospital for a few days. Two others were treated and released with minor burns -- and one firefighter was taken to Sharp Chula Vista for treatment of an ankle injury. He has since been released. 

Authorities shut down both directions of H Street from Broadway to I-5.

The cause of the fire was under investigation.