2 Firefighters Injured in Industrial Blaze : Fire: Sunbird Enterprises, a patio furniture company, and HP Marine are heavily damaged in Costa Mesa.

Firefighters battled for more than four hours Friday morning to extinguish a stubborn two-alarm blaze at a light industrial complex that raged through two businesses and injured two firefighters.

The fire, reported at 5:11 a.m., destroyed three units in the low-slung building in the 1700 block of Monrovia Avenue, Costa Mesa Fire Department spokeswoman Susan Wood said.

“They’ve been pouring water on it all morning,” said Wood as firefighters from an engine company sprayed thousands of gallons of water on the smoldering ruins and caved-in roof. “They can’t get it to go out.”

The fire appeared to have started in an end unit occupied by Sunbird Enterprises, a patio furniture company. Wood said the cause of the fire had not been determined.

The fire was difficult to put out because flames were feeding on tall stacks of polyurethane foam padding used to stuff cushions, she said.

The fire spread to the adjoining business, HP Marine, before it was controlled late in the morning.

Even then, fire officials worried that a section of the prefabricated building’s end wall might collapse. The concrete wall, partly separated from the rest of the building, is supported by metal braces.

Firefighter Fred Seguin was taken to Hoag Hospital in Newport Beach for observation when he complained of abdominal pain after being hit with a stream of water, Wood said.

Firefighter Jeff Janzen was treated at the scene for a “tweaked knee.”

Accurate damage estimates were not immediately available, Wood said, but she noted that the patio furniture business was completely destroyed, while HP Marine sustained heavy damage.

“It’s trashed,” Wood said about the patio furniture business that was in the building’s two end units. “There’s nothing salvageable in there.”