Goshen, Ind. — The state has fined a northern Indiana fertilizer distribution plant $6,750 and a welding company $5,250 for an explosion that reportedly sent a tank airborne at the plant in October and injured four people, three of them seriously. According to the Indiana Department of Labor, T & T Fertilizer Inc. and Southwest Enterprises LLC of Goshen have paid the fines. Both companies also have completed the required abatement outlined in the safety orders, according to Robert Dittmer, department spokesman. While investigating the explosion of a tank during welding, the state found that T & T failed to post danger signs, that both companies failed to provide a safety shower area for workers exposed to corrosive materials, and that cutting or welding was allowed in the presence of explosive gases or liquids. Inspectors concluded that the employer had permitted welding on a tank containing aqua ammonia that “had not been cleaned sufficiently to make absolutely certain there were no flammable materials present.” In all, the state found 16 workplace safety violations, and all were categorized as “serious.” All fines were paid without protest, according to Dittmer.