MINERAL SPRINGS, N.C. — Officials say the two crew members killed in a freight train crash in North Carolina that crumpled train cars and forced evacuations of nearby homes were from South Carolina.

CSX spokesman Bob Sullivan says 36-year-old Greg Hadden of Greenwood, S.C., and 33-year-old Phillip Crawford Jr. of Abbeville, S.C., were killed early Tuesday when one train traveling east through the Union County town of Mineral Springs struck another from behind.

Two crew members were treated at the scene.

Federal authorities are investigating the crash that sparked a fire that burned throughout the day. National Transportation Safety Board spokesman Peter Knudson said the full investigation could take more than a year, though preliminary findings could be released sooner.

Officials say the six families evacuated have been allowed to return home.