WMATA report: Inspector deleted data about track defect that led to derailment

Human error and failed rail fasteners were contributing causes of the Aug. 6 derailment of a Washington Metropolitan Area Transit Authority (WMATA) train, according to a technical incident report the agency released late last week.

On July 9, an employee operating a track geometry vehicle (TGV) identified the "Level Black" rail defect, meaning that the problem needed to be addressed immediately because the track could fail with continued operations. However, the employee mistakenly deleted information about it from the exception report. The report was then passed on to maintenance crews for scheduling immediate repairs to the rail system, WMATA officials said in a press release.

Under protocols at the time, the employee's report with the erroneously deleted information was not subject to review by any WMATA supervisor, and the underlying data was not analyzed by other departments for errors until after the derailment occurred.

"In reviewing the TGV inspection process, we have learned that the derailment was caused by a combination of human error and flawed Metro processes," said WMATA Safety Committee Chairman Michael Goldman. "While the employee believed he was deleting a routinely detected anomaly and not an actual rail defect, that such a serious error went undetected with no checks and balances in place reveals gaps in Metro’s safety policies and procedures."

The TGV operator and a supervisor have since resigned, WMATA officials said.

Additionally, the technical report notes the immediate actions the agency has taken since Aug. 6 to ensure passenger safety, including comprehensive inspections and immediate repairs of defects.

WMATA's board will review the report and ask agency officials questions at a Sept. 3 meeting.

The agency's safety department still is investigating why the wide gauge condition and broken fasteners went undetected by track workers who inspected the area of track on multiple occasions between the TGV run on July 9 and the derailment in early August.

No passengers were on the train during the incident, although it occurred just before boarding.