Indiana fertilizer plant explosion kills one person Updated 8:06 p.m. UNION MILLS, Indiana Authorities say an explosion at a grain bin in northwest Indiana left one person dead. James Swank, 67 The cause of the explosion at Union Mills Co-op Monday afternoon was not immediately clear. The department says in a news release that the victim, 67-year-old James Swank, was a co-op employee believed to be working in the silo when the blast happened. CBS News affiliate WSBT in South Bend, Ind., reported that evidence from the scene indicates Swank may have been on top of a tower at the LaPorte when a possible grain dust explosion occurred and knocked him off the tower. Police say Swank fell about 175 feet. Deputy Neil Lachmund says all other people are accounted for after the explosion, and two others were being checked for injuries. Union Mills Co-op about 50 miles southeast of Chicago. A statement released by the department also said that no hazardous chemicals were involved in or released in the explosion. Unknown number of unsafe fertilizer plants CBS News affiliate WSBT in South Bend, Ind., reported that the Indiana Occupational Safety and Health Administration is launching an investigation into the blast and worker's death. A spokesperson for the agency ran a records check for WSBT and found no records of previous inspections at the plant in response to a complaint or accident. The blast follows one less than two weeks ago at a chemical plant in Louisiana that makes fertilizer. That blast killed done worker and injured seven others. An April 17 fertilizer plant blast in West, Texas, killed 15 people.