New York CNN  —  Norfolk Southern on Tuesday faced harsh criticism from regulators for its decisions immediately after a February 2023 derailment in East Palestine, Ohio. During an all-day hearing in the town itself, hosted by the National Transportation Safety Board, the harshest criticism focused on the railroad’s advocating for a controlled explosion and burn of five tank cars full of vinyl chloride, a toxic chemical three days after the derailment. Norfolk Southern told public officials who authorized the controlled burn, known as a vent and burn procedure, that it was the only way to prevent a catastrophic and uncontrolled explosion. But the NTSB staff and board members insisted at the hearing Tuesday that was not the case. Paul Stancil, an NTSB hazardous materials investigator, said that representatives from Oxy Vinyl, the shipper who owned the five tank cars of vinyl chloride, did not believe the procedure was justified by the facts available at the time. But Stancil said that information was not communicated to the public officials who had to make the final decision. “Norfolk Southern… compromised the integrity of the vent and burn decision by withholding complete and accurate expert opinion and information from the incident commander,” Stancil said. “Vent and burn is a seldom-used procedure,” he continued. “(It) should only be used when there is a high probability of catastrophic tank shell failure.” He said that was not the case here, as evidence from the scene showed no evidence that an uncontrolled explosion was likely. In a statement, Norfolk Southern defended the decision, stating it made the recommendation based on the best available information at the time and that it did not withhold any information. “The NTSB mischaracterized the basis of the recommendation,” said the railroad’s statement. “Several key factors indicated the strong possibility of a catastrophic, uncontrolled explosion.” “The vent and burn effectively avoided a potential uncontrolled explosion,” Norfolk said elsewhere in its statement. “There was no loss of life, injuries, or damage to property, and contractors took steps to manage environmental impact.” NTSB Chair Jennifer Homendy harshly criticized Norfolk’s statement, calling it “insulting.” She said it wrongly tried to shift blame to the public officials who listened to Norfolk’s recommendation to authorize the controlled burn. She said the public officials “did absolutely nothing wrong, who did a phenomenal job with the limited information they had in a very chaotic situation,” she said. “It’s disgusting that anyone would say that.”