(CNN) — Texas State Fire Marshal Chris Connealy said Thursday that the cause of the April 17 fire that led to explosions that killed 15 people is “undetermined.”
“The cause cannot be proven to an acceptable level,” Connealy told reporters.
The fire and explosion occurred at a fertilizer plant in the small town of West, about 20 miles north of Waco and about 70 miles south-southwest of Dallas.
SEE ALSO: West, Tex. explosion coverage
Two blasts — which happened about 30 minutes after the first report of a fire in the facility’s fertilizer and seed building — registered on seismographs as a magnitude-2.1 earthquake and were felt 50 miles away.
The blasts damaged numerous homes, a nursing home and the town’s high school and middle school, all of which had been built withing a few hundred feet of the plant.
