The U.S. Chemical Safety Board (CSB), an independent federal body charged with investigating industrial accidents, has accused a federal law enforcement agency of interfering with its probe of the fertilizer plant explosion in Texas last month.

In a letter to Senator Barbara Boxer (D-California), chair of the Senate Environment and Public Works Committee, CSB’s top official wrote that the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) and the Texas state fire marshal had blocked CSB investigators from examining the accident site.

“To date, the CSB has experienced significant obstacles that potentially compromise and delay our ability to complete the ‘comprehensive investigation’ that you have rightly demanded, and that we would very much like to produce,” Rafael Moure-Eraso, CSB’s chairman, wrote.

Moure-Eraso also wrote that the “incident site was massively and irreversibly altered under the direction of ATF personnel, who used cranes, bulldozers and other excavation apparatus in an ultimately unsuccessful quest to find a single ignition source for the original fire.”

CSB believes the cause of the fire was likely an accident, making it unnecessary to treat the site as a crime scene. But that’s how ATF and the Texas fire marshal have proceeded, preventing CSB officials—including two presidential appointees to its board—from entering the former plant.

ATF has said it was the fire marshal’s decision to bar CSB from the site.

“We have to protect evidence,” Fire Marshal’s Office spokeswoman Rachel Moreno told the Austin American-Statesman. “We need to have one report, one set of interviews; it all has to be clear cut.”

CSB claims ATF and the fire marshal have not taken care to protect company documents left at the plant, saying papers have been seen “blowing around” the area and being exposed to rain.

Boxer plans to hold hearings on the accident, which left 15 people dead and more than 200 injured.

-Noel Brinkerhoff

To Learn More:

Federal chemical safety agency complains of lack of access to West blast site (by Todd Gilman, Dallas Morning News)

Chemical Safety Board says ATF, Texas fire marshal blocking its probe of fatal plant blast (Associated Press)

U.S. Board with no Power Tells State to Change Safety System It Blames for Refinery Fire (by Ken Broder, AllGov California)

Regulation Loophole Exempted Texas Fertilizer Plant From Stringent Inspections and Rules (by Noel Brinkerhoff and Aaron Wallechinsky, AllGov)

Texas Fertilizer Company Hid Dangerous Materials from Regulators (by Noel Brinkerhoff, AllGov)