PRINCETON, Ind. (AP) — Officials say a buckled stretch of track is believed to have caused a fiery freight train derailment in southwestern Indiana that belched black smoke into the sky and forced the evacuation of nearby homes. The Evansville Courier & Press reports that the update on the investigation comes in a report to the Federal Railroad Administration from rail operator CSX. The derailment happened June 17 near a trailer park in Princeton, about 150 miles (240 kilometers) southwest of Indianapolis.