The National Transportation Safety Board has issued a safety alert to subway systems and commuter railroads over a wheelset problem that led to a derailment in the nation’s capital in October.
The agency says the defect can be easily missed without careful inspection and that a derailment “could be catastrophic.”
The NTSB released a preliminary report of its ongoing probe into the accident involving the Washington subway system.
The NTSB is urging transit agencies to comply with a recent federal directive to conduct detailed inspections for misaligned wheels.
The bulk of Washington’s Metro fleet has been suspended from service since mid-October after a train car slipped off the tracks.