The letter singled out a regulation on notifications related to trains carrying hazardous or flammable material, asking if it made sense that such trains only of a certain size should have to notify local communities. A spokesman for the agency said it had no immediate response Wednesday. "We don't really have much to say other than we appreciate the leader's commitment to safety," NTSB spokesman Keith Holloway said in a phone interview. "We are reviewing the letter and we'll respond to him." Rail owned by the seven Class I freight railroads: BNSF, Canadian National, Canadian Pacific, CSX, Kansas City Southern, Norfolk Southern and Union Pacific. Focus on profits In remarks on the Senate floor, Schumer said a "questionable safety culture" at Norfolk Southern was at least partially to blame for the East Palestine derailment. Railroads' focus on profits had led to a lax safety culture in the industry generally, he said.