The National Transportation Safety Board determined today that the probable cause of the derailment of a Norfolk Southern train in New Brighton in 2006 was a broken rail and blamed the railroad's "inadequate rail inspection and maintenance program."

The NTSB said the rail fractured from an "undetected internal defect."

The board also said that a contributing factor was the Federal Railroad Administration's "inadequate oversight" of the inspection process.

The fiery, 23-car derailment on Oct. 20, 2006, dumped 485,000 gallons of denatured ethanol into the Beaver River and forced emergency personnel to evacuate hundreds of residents.

More details in tomorrow's Pittsburgh Post-Gazette.