While the Trump administration continues its push to stymie and roll back federal regulations by fighting in court to uphold a delay of the Chemical Disaster Rule, hazardous materials crews are searching for a worker presumed dead after an explosion at a Texas chemical plant.

Two other workers were injured Thursday in the blast at the Tri-Chem Industries plant in Cresson, which is about 50 miles southwest of Dallas. Efforts to battle the blaze were temporarily halted by concerns about exposure to toxic fumes and the subsequent explosions.

Cresson Mayor Bob Cornett told The Associated Press that the plant “mixes chemicals that are primarily used by the oil and gas industry to drill disposal wells,” though he didn’t know the specifics.

A spokesman for the Texas Commission on Environmental Quality refused a request by AP to provide a list of the plant’s chemicals, telling the journalist to file an official public information request.

“Texas leaders have made it increasingly difficult for the public to find out about the chemicals manufactured and stored at such plants,” the AP noted. Following a 2013 explosion that killed 15 people at a fertilizer plant in West, Texas, the state deemed that agencies could withhold hazardous chemical information because of “ongoing terroristic activity.”

A few months after the West, Texas explosion, then-President Barack Obama signed an executive order that aimed to improve chemical safety at facilities across the country. In response to the order, a final rule (pdf) to strengthen the federal Risk Management Program regulations was published in January 2017, just a week before President Donald Trump took office.