FLAGSTAFF, Ariz. -- Flames from welding equipment touched off a grain-dust explosion at a Nestlé Purina plant on Sunday, severely burning two workers and injuring two others, authorities said. The four contractors were welding about 5 p.m. on the fifth floor of the complex's seven-story grain elevator when their torches sparked grain dust and set off the blast, Flagstaff Fire Department Capt. Bill Morse said.
The explosion did not produce a long-lasting fire but it blew out metal doors at the front of the grain elevator, according to Morse. The U.S. Occupational Safety and Health Administration website says grain dust is the main source of fuel for explosions in grain handling.