OCFA firefighters responded to the 5300 block of Walnut Ave., in Irvine, on Tuesday evening for a fire at a commercial strip center.

Engine 126 was the first-arriving unit and reported smoke from the roof area of a business. A second alarm was requested and subsequently a third which brought over 50 firefighters to the scene.

It took firefighters 43 to get a knockdown. Fire investigators are on scene. No cause determined yet.

A closer inspection found that only one unit was damaged.

Thanks to an aggressive attack, a knockdown was declared and the adjacent businesses were saved.

No injuries were reported.