This photo from the U.S. Chemical Safety Board shows the devastation investigators found near the site of the explosion at the West Fertilizer Co. in Texas.

Originally slated for completion by May 10, the Texas State Fire Marshal’s Office says the investigation of the West Fertilizer Co. fire for at least another week, possibly two. Investigators revealed that ammonium nitrate stored on site detonated in the explosion.

Over 70 investigators from agencies including the State Fire Marshal’s Office and ATF continue the investigation. The two agencies have developed over 200 leads, and conducted more than 400 interviews.  Also on site are federal investigators from OSHA and the Chemical Safety Board.

Investigators have determined the origin of the fire was in the fertilizer and seed building, and are continuing to work on pinpointing an exact location of the fire’s origin within the 12,000-square-foot building.

While the ammonium nitrate did detonate in the explosion, investigators still are trying to determine the cause of the explosion. They also continue to search for the cause of the fire that happened prior to the deadly explosion. 

Investigators have eliminated weather, natural causes, anhydrous ammonium, the railcar containing ammonium nitrate and and a fire within the ammonium nitrate bin as causes for the initial fire. Investigators also have determined that water used during fire-fighting activities did not contribute to the cause of the explosion. 

The investigation into the causes of death for the first responders also continues.

On May 3, U.S. Chemical Safety Board investigator Jerad Denton took a film crew into West, Texas, to document the level of community damage from the fertilizer explosion that killed 14 and injured about 200 others. This 3-minute video shows the devastation in West.

West Fertilizer Explosion Investigation Continues
EHS Today