JACKSON TOWNSHIP | Federal officials are investigating just what caused three freight trains to crash northeast of Valparaiso, sending a thick cloud of black smoke into the air and forcing residents from their homes.

At 1:18 p.m. Friday, Porter County sheriff's police were called to the area of County Road 600 North and County Road 500 East, where they found the flaming wreckage of three CSX freight trains just north of the intersection.

"They were one on top of each other," Sgt. Larry LaFlower said of the tankers and freight cars the locomotives were hauling.

LaFlower said investigators believe a westbound train was stopped on the tracks for an unknown reason and was rear-ended by a second westbound train. The impact caused both trains to derail, and diesel fuel from the second locomotive reportedly set the wreckage of both trains on fire.

A third train, heading west on the adjacent track, was unable to stop and struck the wreckage, further adding to the fiery mess.

LaFlower said two crew members in the second train suffered nonlife-threatening injuries and were taken to Porter hospital in Valparaiso.