WASHINGTON — U.S. Sens. Bob Casey and John Fetterman are pressing Norfolk Southern to join a federal rail safety program that the company said it would join more than four months ago, after one of its freight trains derailed in East Palestine, Ohio in February.

The Federal Railroad Administration’s Confidential Close Call Reporting System allows employees to report near-misses or close calls on railroads and protects them from discipline for reporting such incidents.

Norfolk Southern said in March that it was engaged in a working group on the program and planned to join, noting it would build on its own close-call reporting system and mark “another step we are taking to further our commitment to safety,” according to CEO Alan Shaw.

But the senators, both Pennsylvania Democrats, say the Atlanta-based company hasn’t met its pledge. In a letter to Mr. Shaw, they called the FRA’s close call reporting system “a promising program with real potential to improve rail safety, protect employees, and reduce incidents if adopted by a larger swath of the rail industry.”