Roughly 30 tons of ammonium nitrate, a key chemical found in fertilizer and explosives, vanished from a sealed train car somewhere between Wyoming and California last month, officials said Monday. Four separate investigations were launched into the disappearance of the chemicals, which remain missing, according to KQED. A spokesperson for Dyno Nobel, the company that produced the chemical, said in a statement, “The railcar was sealed when it left the Cheyenne facility, and the seals were still intact when it arrived in Saltdale. The initial assessment is that a leak through the bottom gate on the railcar may have developed in transit.” In a statement to NBC News, a spokesperson for rail carrier Union Pacific said that “at this point in the investigation, we do not believe there is any criminal or malicious activity involved,” but noted that the inquiry was still “in its early stages.” The spokesperson added that if the ammonium nitrate, which was transported in pellet form, did leak out during the journey, “the release should pose no risk to public health or the environment,”