Workers were back on the job Tuesday after a three-alarm fire at a Johnstown manufacturing plant.

The fire happened at North American Hoganas on Bridge Street in the Moxham section of the city on Monday. Officials said they believe an explosion in an electronic furnace sparked the three-alarm blaze that caused the plant to evacuate.

There are seven furnaces total on the property; three of which are on the floor where the fire happened. Tuesday, employees were back at work in other buildings at the plant and officials are looking for a cause.

There were no reported injuries.

The company's president said a new liner had recently been installed on the third floor furnace and workers were melting materials to season it, when one man spotted flames shooting from the furnace. He alerted coworkers and they ran for an exit. On the way, they reported hearing the explosion.

Workers said they are trained to respond to situations like this and all proper procedures were followed. Company officials are assessing damages on Tuesday and said that repairs will be made.

The location of the fire made it more difficult for crews to extinguish it, Johnstown Fire Chief Anthony Kovacic said.