FALLS CHURCH, Va. - On Thursday, the National Transportation Safety Board released the cause of the July's Metro train derailment when a Metro Silver Line train line derailed near the East Falls Church station.
NTSB says Metro's ineffective inspection and maintenance practices are to blame for the July 29 incident.
"The probable cause of this accident was a wide track gage condition resulting from the sustained use of deteriorating wooden crossties due to Washington Metropolitan Area Transit Authority's ineffective inspection and maintenance practices and inadequate safety oversight," NTSB announced in a statement Thursday.
Investigators with NTSB noted that the track gage measurement near the point of derailment was nearly two inches wider that acceptable by WMATA standards.
"WMATA has standards that address defective crossties; however, it was not apparent that the track structure in the accident area was consistently maintained to those standards," the report says.
They also found that WMATA track standards require there be no more than 120 inches between non defective rail fasteners for tracks of similar construction, and in this accident area, investigators noted over 400 inches of track with no effective rail fasteners because of deteriorated crossties.
Around 63 passengers were on board the train at the time of the accident, all were evacuated and three passengers reported injuries, only one was taken to the hospital.
The full NTSB report can be viewed below: