Coal barn attendant reported the smell of coal burning at 11:20 am. He inspect coal storage barn, noticed area appeared to be smoldering. He attempted to extinguish, air monitor alarmed. Operator notified supervisor 12:05pm. At 12:10pm, supervisor restricted entry. Contacted Ishpeming Township Fire Dept, ITFD extinguished the smoldering coal. ITFD off-site 2:45 pm.