Officials: No Evidence Paramedic Arrested over Pipe Bomb Linked to Fertilizer Plant Explosion

Cause of the detonation still under investigation

Prosecutors charged a paramedic, one of the first to respond to a deadly explosion last month in West, Texas, with unlawful possession of pipe bomb components, although authorities said no evidence linked the charge to the fertilizer plant disaster.

Texas state officials also announced on Friday that they had opened a criminal investigation into the April 17 explosion that killed 14 people and injured about 200 others. The state fire marshal's office has said that ammonium nitrate stored at the plant detonated in the explosion but they have not been able to pin down the cause of the fire and blast.

The state Department of Public Safety said the Texas Rangers have been directed to join McLennan County Sheriff Parnell McNamara in the investigation.