By SDCN Staff

La Mesa, CA–A structure fire that broke out Wednesday at an office supply store in the east county is under investigation, fire officials said.

La Mesa Police Department and 18 fire crews from Heartland Fire and Rescue, San Diego, Lakeside, and San Miguel Fire Departments responded to the fire at about 4:44 p.m. in the Office Depot at 8481 Fletcher Parkway.

The sprinkler system inside the building was activated and kept the fire in control. The blaze was reported knocked down by fire crews at approximately 5:25 p.m., according to fire officials.

No serious injuries to civilians or firefighters were reported, however one Office Depot employee was evaluated on scene by paramedics, and was subsequently released.

Estimated damage to the structure and contents is over $1 million. 

The cause of the fire is under investigation.