EAST PALESTINE, Ohio (WKBN) – An issue with a wheel was pinpointed as the likely cause of a Norfolk Southern train derailment last March, according to a final report from the Federal Railroad Administration.

The derailment on March 5, 2022, happened in Perryman, Maryland, resulting in the derailment of 20 cars and over $2.66 million in damage to the rail equipment and track. There were no injuries reported.

Almost a year later, the National Transportation Safety Board is now probing an overheated wheel bearing as the possible cause of a train derailment in East Palestine, which led to the evacuation of homes and release of chemicals from the train — some of which made their way into nearby waterways and soil.

The accident investigation report into the Maryland train derailment details that the train went into emergency after Norfolk Southern determined that a freight car had a broken wheel rim, resulting in the 20-car derailment. The wheel had broken apart while the train was in motion, according to the report. The train was operated by a three-member crew and comprised two locomotives and 130 loaded freight cars.

The faulty wheel had been manufactured in November 1998 by a company in Columbus, according to the report.

The train had been inspected on Feb. 26, 2022, prior to its departure.

The report found that the company had been in compliance with train handling, rules and operational compliance. The report also found that track conditions did not cause or contribute to the accident. The signal system — including the Hot Box Detector — was working as intended and showed no anomalies.

The report did find several mechanical issues with the locomotives and freight cars — including brake issues — and an overdue inspection, but those issues did not appear to contribute to the derailment.

While inspection procedures did not directly cause or contribute to the derailment, the report noted, “increased inspections and inspection frequency may have prevented the derailment by identifying the wheel defect that caused the derailment sooner.”

The report stated that this particular wheel defect could be difficult to detect during a traditional “walking” inspection of the equipment. The report recommended more frequent inspections, including after the train left, and periodic X-ray or ultrasonic testing to find any wheel defects.

The FRA’s last audit of Norfolk Southern, published in July 2022, noted several issues that “may raise the overall risk of train derailment.”

Among the issues noted, the FRA found “inadequate communication” between the company’s transportation and mechanical departments. The audit states that the required equipment inspections were performed, but in some cases, either the defective conditions that were identified by the inspections were not reported to the mechanical department for repair, or the equipment was not removed from service until repairs could be made.

The FRA audit also found instances where Norfolk Southern did not take immediate action to remediate defective conditions, calling it a “concern.”

More recently, a Norfolk Southern train also went off the tracks in Van Buren Township, Michigan, weeks after the East Palestine derailment. No one was injured, and the one car carrying hazardous materials wasn’t affected.

There were more than 12,400 train derailments in the U.S. over the past decade, or more than 1,200 annually, according to Federal Railroad Administration data based on reports submitted by railroads.

Those accidents combined derailed or damaged about 6,600 tank cars carrying hazardous materials — including 348 cars that released their contents — and prompted evacuations involving more than 18,600 people, according to FRA data.

Total damages reported by railroads from derailments of trains hauling hazardous materials exceeded $930 million over the decade, the accident reports show.

U.S. rail accidents from all causes – from derailments to malfunctioning equipment — released more than 5 million gallons of hazardous materials since 2011, according to data collected by the Pipeline and Hazardous Materials Safety Administration. The bulk of what spilled was crude oil, but the accidents also included fuels such as gasoline and ethanol and a wide range of other chemicals.

In East Palestine, crews completed a controlled release of chemicals from the derailed train cars to mitigate any risk of an explosion from the site. The trains were carrying vinyl chloride, benzene residue, butyl acrylate and combustible liquids.

The final cause of the derailment in East Palestine hasn’t been determined yet. The NTSB is continuing that investigation.

The Associated Press contributed to this report.