Investigators are looking into what caused a three-alarm fire at the Donsco iron foundry in Wrightsville on Friday.

Witnesses reported flames as high as 40 feet shortly after the fire started around 10:40 a.m.

More than a hundred firefighters from York and Lancaster counties were called to the foundry in the 100 block of North Front Street.

The fire was brought under control in the afternoon, but hot, molten metal that was slow to cool without power to the foundry kept several crews at the scene.

Three firefighters and an employee were treated at the scene for heat exhaustion.

Phil Smith, the emergency management coordinator for eastern York County, said about 100 employees were in the building when the fire started.

“Knowing Donsco, they train their employees well, I think that showed, that training, and they all got out and they all knew where to go,” Smith said. “They had their evacuation routes and were handled appropriately and tremendously.  Everybody was accounted for in a short amount of time.”

A company spokesperson said second and third-shift employees should not report. Maintenance workers, however, should report as scheduled.

Donsco builds machined iron parts such as manifolds, brackets, gearboxes, transmission housings, and pump castings. The company employs 350 people and has been in business for more than 100 years, according to its website.