A U.S. Senate committee harshly criticized rail operator Norfolk Southern and pressed it to back safety reforms on Thursday after a devastating February 3 derailment in East Palestine, Ohio, of a freight train carrying hazardous materials.

Since the Ohio derailment that caused cars carrying toxic vinyl chloride and other hazardous chemicals to spill and catch fire, Norfolk Southern has been under pressure after a number of derailments of its trains.

During a three-hour long hearing, senators from both parties said Congress must pass rail safety reforms and pressed Norfolk Southern CEO Alan Shaw to endorse improvements.

"It's our responsibility in Congress to answer: What went wrong? What do we need to do to fix it? What can we do to make sure it does not happen again?" Senate Environment and Public Works committee chair Tom Carper said in opening the hearing.

Late on Thursday, the Senate Commerce Committee confirmed Shaw will appear on March 22 at a rail safety hearing, as will National Transportation Safety Board Chair Jennifer Homendy.

Senators asked Shaw to do more to compensate local residents, boost staffing and spend more on safety improvements, as well as questioned the company's spending on stock buybacks and sharp cuts in staffing over the last decade.

At the hearing Shaw apologized, pledging to improve safety and address impacts including thoroughly cleaning the site. He said it had already committed $21 million to the community as a "down payment... I am committed to doing what's right for the community."

He said the railroad was committed to the "legislative intent to make rail safer" but did not endorse the bill.

Shaw defended Norfolk Southern's safety record and has pledged to make immediate safety improvements. At the hearing, one senator noted that another train operated by Norfolk Southern on Thursday derailed in Alabama.

Shaw said on Thursday that in December he directed the railroad to "move away from a near-term focus solely on profits and that we're going to take a long-term view."

Ohio Democratic Senator Sherrod Brown said Norfolk Southern used much of its "massive profits" to hike executive pay and pay shareholders rather than on safety measures. "This company has failed to its job over and over and over," Brown said, saying the railroad eliminated 38% of its jobs over a decade.

Shaw said the railroad is on a "hiring spree" and has added 1,500 jobs over the last year but it is still far below where it was.

A bipartisan group of senators led by Brown and Ohio Republican J.D. Vance introduced legislation last week to prevent train disasters. It would require enhanced safety procedures for trains carrying hazardous materials, as well as require wayside defect detectors, a minimum of two-person crews and increased fines for wrongdoing.