Louisville Emergency Management Agency Doug Hamilton says the workers were critically injured Wednesday with second- and third-degree burns covering 90 percent of their bodies. He says two others were injured but refused to be taken to the hospital.
Hamilton says the workers were wearing respirators and they were using a blow torch, but he wasn't sure why.
Firefighters are trying to put out the blaze.
A Paducah & Louisville Railway train carrying hazardous chemicals derailed just after 6 a.m. EDT Monday. A leak of a potentially explosive material was contained, but crews have been working to put the railroad cars back on the track or remove them.