The two men trapped under rubble at an Ohio County surface mine have been identified as blasters at a company called MEMSCO, which also does business as the Mine Equipment and Mill Supply Company. MEMSCO has an office in Dawson Spring, Kentucky, but is owned by Midland Powder Company in Evansville, Indiana.According to federal mine inspection records, the Mine Equipment and Mill Supply Company was cited by the Mine Safety and Health Administration as recently as July for a “significant and substantial” violation. The violation stemmed from the operation of the company’s loading and haulage equipment.The company has been cited nearly 50 times in the past two years for work at other coal mines and quarries. Twenty-one of those violations were categorized as “significant and substantial” by MSHA.