WACO, Texas (AP) -- Texas law enforcement officials are launching a criminal investigation into last month's deadly fertilizer plant explosion.
Investigators have up to now largely treated the West Fertilizer Co. blast that killed 14 people as an industrial accident.
The Texas Department of Public Safety said in a Friday statement that the agency has instructed the Texas Rangers and the McLennan County Sheriff's Department to launch a criminal probe.
DPS Director Steven McCraw says in a statement he wants to ensure "no stone goes unturned" in the investigation.
The plant blew up on the night of April 17 after a fire erupted at the facility in the rural town of West.