The two people most seriously injured in a railcar explosion in northeast Kansas are improving at a Kansas hospital.

The men were among at least seven people hurt when the railcar exploded Thursday at GBW Rail Services west of Atchison.

A spokesman for the University of Kansas Hospital said early Friday that the men’s condition had been upgraded to fair.

No one was killed. The Kansas State Fire Marshal’s Office is investigating the cause of the accident.

Atchison County Sheriff Jack Laurie says the rail car exploded inside a building. The 16 or 17 employees in the area were all accounted for after the explosion.

GBW official Jack Isselman said the explosion happened in an area where rail car surfaces are prepared for painting.