Philadelphia, May 19 (RHC)-- In the United States, Amtrak says it has installed automatic train control technology that slows trains on the stretch of track where last week’s deadly derailment occurred. Federal officials have ordered the installment of a more advanced system, positive train control, by year’s end.

Full service is resuming on the Northeast Corridor train line today after repairs were made. Federal officials continue to investigate the derailment’s cause amid conflicting accounts surrounding the engineer.

After interviewing crew members, Robert Sumwalt of the National Transportation Safety Board said one may have heard the engineer reporting the train was hit by an object.