A contractor is being blamed for causing a gas leak that led to a fatal house explosion in Barnhart in February. The Occupational Safety and Health Adminstration suggests a 15-hundred-dollar fine for A-B Contracting of Herculaneum. The company has two weeks to appeal. OSHA says the company did not try to locate a natural gas main while digging in a subdivision. The agency says the gas migrated through the soil into a house that blew up, killing a man inside. Six other homes sustained structural damage and a dozen others had lesser damage.