Texas authorities are launching a criminal investigation into last month's deadly fertilizer distribution facility explosion in West, Texas, the Texas Department of Public Safety said Friday.
The announcement was made on the same day authorities arrested Bryce Reed, a West emergency volunteer who was a first-responder to the disaster.
Authorities have not tied the arrest to the deadly blast.
McLennan County sheriff's records clerk Betty Duncan told CNN that Reed was arrested for possession of a destructive device, booked early Friday, and is in the custody of U.S. Marshals.
Reed spoke at a memorial for the victims at Baylor University.
"This disaster has severely impacted the community of West, and we want to ensure that no stone goes unturned and that all the facts related to this incident are uncovered," DPS Director Steven McCraw said.
The April 17 fire and explosion at West Fertilizer Co. killed 14 people and devastated the small town of West.
On Monday, the state fire marshal's office said it ruled out four potential causes: weather, natural causes, anhydrous ammonium, and ammonium nitrate in a rail car.
The fire began in the fertilizer and seed building, but authorities still were trying to figure out the exact spot, the fire marshal's office said Monday.
The blast happened about 20 minutes after the first report of a fire at the fertilizer facility. It registered on seismographs as a magnitude-2.1 earthquake and could be felt 50 miles away.
The explosion damaged numerous homes, a nursing home and the town's high school and middle school, all of which were built within a few hundred feet of the plant. West is about 70 miles south-southwest of Dallas,
Scores of investigators have followed up on scores of leads relating to the explosion. At least 60 investigators have been on site each day and have conducted 411 interviews in trying to determine how the fire started and what caused the explosion.