UPDATE: Flash Fire at West Des Moines Plant Injures Four

An overhead sprinkler system saved the lives of four Goodrich Engine Co. workers Wednesday after a fireball erupted near their work stations, West Des Moines Fire Marshal Mike Whitsell said in an interview with Patch. 

"They were very fortunate," Whitsell said of the four workers, who were treated for minor burns at the scene by paramedics. "The fire sprinkler system activated within seconds, and it's safe to say the sprinkler system saved lives and protected the plant."

The fire call from the business at 811 Fourth St. came in about 8 a.m. from a Goodrich employee who reported "a large fireball in the back of the building," Whitsell said. 

Fire investigators have not yet isolated the source that ignited the fire, Whitsell said.

Fire officials told KCCI.com that employees were testing a flow injector on a turbine engine. They sent solvent through that engine, which caused a fire ball. The building's sprinkler system put out the fire, KCCI said.

"We don't know the ignition source of the solvent," Whitsell told Patch. "Something — a mechanical short, static electricity, there's a wide range of ignition sources — started it."

Fire investigators have completed their preliminary investigation, Whitsell said. Owners and the company's investigators are inspecting equipment to determine the extent offire, smoke and water damage, he added.

Officials said 350 employees were evacuated and sent to other company locations in West Des Moines.

Patch.com saw the two engines that responded to the fire leaving the scene around 9 a.m. There was no smoke visible at any time from outside the building.