60,000 pounds of an explosive chemical lost during rail shipment, officials say

About 60,000 pounds of a chemical used as both a fertilizer and an explosive is missing after likely disappearing during a rail trip from Wyoming to California last month, according to federal records.

A rail car carrying ammonium nitrate left a plant operated by explosives manufacturer Dyno Nobel in Cheyenne, Wyoming, on April 12, according to an incident report filed by a representative of the company with the National Response Center on May 10.

The report states that the chemical was released "due to an unknown cause," and that it was discovered missing after the rail car arrived in Saltdale, California, an unincorporated community more than 1,000 miles from Cheyenne.