WASHINGTON (AP) — A top federal transportation safety official on Thursday harshly criticized Washington’s regional transit agency, saying a “poor safety culture” led to an October 2021 derailment that caused hundreds of new Metro rail cars to be pulled from service.

A final National Transportation Safety Board report on the incident concluded that the Washington Metropolitan Area Transit Authority had been aware for years of a safety issue that caused the wheels on the new 7000-series Metro cars to expand wider than the tracks. However, NTSB Chair Jennifer Homendy said that information was poorly communicated within the organization and not acted upon with the proper urgency.

“This incident was 100% preventable,” Homendy said at a news conference. “We’re absolutely lucky that this did not end in a tragedy.”

On Oct. 12, 2021, an eight-car train slipped off the tracks on Metro’s Blue Line near Arlington National Cemetery in northern Virginia. Some passengers were trapped in a tunnel in a dark train car and had to be evacuated on foot, but there were no serious injuries.

Homendy said in 2021 the car had apparently derailed once earlier in the day, and then re-connected with the rails by itself, before derailing a second time. On Thursday, she said that further analysis had revealed two separate incidents where the train car briefly derailed and then corrected itself.

The derailment and the ensuing investigation helped speed the ouster of former WMATA general manager Paul Wiedefeld.

After announcing his retirement date of July 2022, Wiedefeld left two months early in May 2022 amid revelations that half of WMATA’s train operators had lacked retraining and testing required for recertification. Wiedefeld has served as Maryland’s secretary of transportation since his appointment by Gov. Wes Moore in January 2023.

Without mentioning Wiedefeld by name, Homendy seemingly laid much of the blame on his administration. She praised new general manager Randy Clarke for embracing the investigation process and installing a rigid inspection regime while the wheelsets on 748 separate train cars are replaced.

“I want to commend Randy Clarke for taking this seriously,” Homendy said. “You don’t always get that during an investigation.”

The 7000-series cars, about 60% of the fleet, are gradually returning to service and subject to monthly inspections. So far 199 of the 2,992 wheelsets have been replaced.

WMATA said in a statement that it “fully supports the NTSB Derailment report and thanks all parties to the investigation for their leadership and thoughtful approach. The collaboration and professionalism between the NTSB and WMSC (Washington Metrorail Safety Commission) have been critical to our ability to move this process forward, and we appreciate that our proactive steps have been acknowledged.”

However, a fight looms over who will pay for the repairs — WMATA or the cars’ manufacturer Kawasaki. The WMATA statement specifies that the agency, “has issued a fleet defect notice to Kawasaki related to our performance-based contract. Based on the contract, Kawasaki is responsible to pay all costs to fix this wheelset defect.”

The transit authority estimated the cost of repairs at $55 million.

Kawasaki laid the the blame on the agency in a statement, saying that WMATA provided inaccurate instructions and muddled communications and didn’t inform Kawasaki of a looming problem despite evidence dating back to 2014.

“While we understand the budget crisis that WMATA is facing, any suggestion that Kawasaki should absorb the cost of WMATA’s own failures regarding the wheelsets of the 7000 series trains is not rooted in reality,” the company’s statement said. “The mismanagement by WMATA under prior leadership, cited in the NTSB’s final report, comes as no surprise to those who have followed the agency.”

Maryland, Virginia and the District of Columbia share the costs of funding the Metro system, which is studying service cuts as it faces a reported $750 million budget shortfall for fiscal 2025. MDOT expects to be responsible for about $150 million per year in fiscal years 2025 and 2026, Wiedefeld recently said, under the shared funding structure to which MDOT is committed.

This is contributing to a $3.3 billion hole in funding Maryland’s six-year transportation plan, a gap that threatens to delay Maryland transportation projects and trigger cuts in local commuter bus service and roadway maintenance.

Since taking the helm of the state transportation department, Wiedefeld has had to grapple with safety issues on Baltimore-area transit lines as well.

On Dec. 7, the Maryland Transit Administration suspended service on the Baltimore region’s light rail line due to safety concerns over defects in recent rehabilitation work on its rail cars. The service outage lasted nearly two weeks.

“I thank our dedicated Maryland Transit Administration employees and our contractor’s workforce for all they’ve done to advance these reviews while maintaining safety as our highest priority,” Wiedefeld said in a recent press release, in which he also thanked riders for their patience. The MTA is part of the state Department of Transportation, which Wiedefeld oversees.

In 2008, when he headed the MTA, Wiedefeld ordered a similar service shutdown due to safety concerns with the light rail cars’ wheel and braking system.

In July, an electrical fire on Baltimore’s subway line prompted MTA officials to suspend service for five days.

Banner reporter Daniel Zawodny contributed to this report.