Wagons with loose wheels were found during the cleanup of East Palestine, Norfolk Southern reports

Norfolk Southern is a railroad company whose the train derailed last month in East Palestine, Ohio, contaminating the surrounding area with toxic chemicals – announced Thursday night that it had determined that some of its railcars of a certain make and model had loose wheels.

While clearing the scene of the derailment, Norfolk Southern investigators discovered that “a specific model and series of cars have loose wheels,” the company said in a statement Thursday evening, calling the discovery an “urgent safety concern.”

The wheels came from “a series of recently purchased vehicles from a specific manufacturer,” Norfolk Southern said.

Norfolk Southern did not name the manufacturer or say whether or how many of the cars involved in the East Palestine crash were part of that model and series.

The Federal Railroad Administration and the National Transportation Safety Board were “immediately notified and have begun an inspection of other cars in this series on our network,” Norfolk Southern said.

The company added that the cause of the crash is under investigation.

The announcement came on the same day as Norfolk Southern CEO Alan Shaw appeared before a Senate panel to consider the crisis in eastern Palestine and several recent incidents on Norfolk Southern train tracks, including one earlier Thursday in Alabama. Shaw promised that the company would “carefully and urgently clean up the site. We’re making progress every day.”

He added that the company also planned $20 million in compensation and investment for families and first responders affected by the incident.

On February 3, a Norfolk Southern train was carrying hazardous materials went off the rails in a fiery disaster in Eastern Palestine. Of the 38 cars that derailed, about 10 contained dangerous substances. Hundreds of residents were evacuated, and later crews conducted a controlled release of toxic chemicals, including vinyl chloridebecause of the risk that a derailment could cause an explosion.

State and federal officials have faced significant criticism for their response to the incident in East Palestine concerned local residents that contamination of the area may pose a significant long-term health hazard.