One employee of railway car manufacturer FreightCar America was killed and three more were injured before the shooter—believed to be a current or former employee—committed suicide.

A gunman opened fire at FreightCar America early Tuesday morning, killing one employee, injuring three others and then killing himself, police said.

The deceased victim is a FreightCar employee. The assailant is thought to be either a current or former employee, according to Roanoke Police Chief Tim Jones.

Three victims were taken to Carilion Roanoke Memorial Hospital for treatment of gun-related injuries. One was in serious condition, said Carilion spokesman Chris Turnbull. The other two were considered in good and fair condition.

FreightCar America employs a few hundred workers in what is known as Norfolk Southern’s East End Shops along Campbell Avenue Southeast.

Police responded to the rail car maker’s plant on reports of gunfire at 6:08 a.m. Police said there was one witness to the shooting who had been in the restroom.

It is not known how many employees were on the third shift. Day employees began reporting for their 7 a.m. shift to find emergency workers and police on the scene.

About a hundred people in hardhats stood outside while police moved in and out of the plant throughout the morning.

Norfolk Southern also placed a hold on people going into the yard. By 10:25 a.m., railroad employees were cleared to enter the building, spokeswoman Susan Terpay said.

Jones said it is believed the shooter turned his weapon on himself. No police were injured, nor did they fire their weapons, he said.

We’ll update this story as more information becomes available.