U.S. Senators from both sides of the political aisle in Ohio and Pennsylvania say they’ll used information about the chemical train derailment and fire in East Palestine to make changes designed to prevent similar incidents in the future.

Senators Bob Casey (D-PA), John Fetterman (D-PA), Sherrod Brown (D-OH), and J.D. Vance (R-OH) sent joint letters to the Environmental Protection Agency and National Transportation Safety Board.

In the letter to the NTSB, the Senators highlighted rail safety concerns they have heard from constituents, rail experts, and railroad workers as the NTSB conducts its investigation into the derailment.

The NTSB letter says the senators will use the board’s findings and any pertinent safety recommendations to advance measures that Congress and the U.S. Department of Transportation can implement to prevent derailments involving hazardous materials.

The NTSB has said it expects to issue preliminary findings of its investigation in less than two weeks.

In a letter to the EPA administrator Michael Regan, the Senators supported the EPA’s plan to hold Norfolk Southern accountable for releasing hazardous materials into the air and water.

The EPA's Regan is scheduled to visit East Palestine on Thursday.