SAN ANTONIO - Investigators have determined that ammonium nitrate was the cause of the explosion at a West,Texas, fertilizer plant last month that left 14 people dead and about 200 injured, a spokeswoman for the Texas fire marshal's office said Tuesday.
"The investigators have been able to narrow down the origin to the fertilizer and seed building on site, and we also know that what caused the explosion was the ammonium nitrate," said Rachel Moreno, a spokeswoman for the Texas State Fire Marshal's Office. "What we don't know is exactly why."
The fire marshal's office has been leading the investigation of the April 17 blast, along with the federal Alcohol, Tobacco, Firearms and Explosives agency (ATF).
Ammonium nitrate is a dry fertilizer mixed with other fertilizers such as phosphate and applied to crops to promote growth. It can be combustible under certain conditions, and was used as an ingredient in the Oklahoma City bombing in 1995 that left 168 people dead.
Also, federal emergency officials have begun offering shelter for West residents whose homes were destroyed or severely damaged. About 70 homes were damaged or destroyed.
A statement from the Federal Emergency Management Administration said the transitional sheltering assistance was requested by Texas officials, the Associated Press reported. It would allow those whose homes were left uninhabitable by the blast to stay for a limited time in a hotel or motel at government expense.
Meals, telephone calls and other incidental charges are not covered, and applicants are responsible for any lodging costs above the authorized lodging costs, according to the statement. Eligible applicants are being notified.