CSX Corp. says it has determined what caused a train carrying crude oil to derail on a bridge over a river in Philadelphia.
WPVI-TV reported Thursday that a CSX investigation determined a maintenance crew replacing crossties didn’t follow procedures and failed to properly anchor temporary fasteners to the ties.
The train derailed Jan. 20 on the Schuylkill Arsenal Bridge.
CSX said the maintenance work was not related to the structural integrity of the bridge, which remains sound.
Although no oil spilled and no one was hurt, the derailment caused concern because it occurred in a densely-populated area over the Schuylkill River, near the University of Pennsylvania, a highway and three hospitals.
The CSX report is subject to review by the Federal Railroad Administration.