The Smith Mine was the site of the worst underground coal mine disaster in Montana history, where 74 men died on the morning of February 27, 1943. Smoke pouring from the entrance to the No. 3 vein was the first sign of trouble, and the hoist operator, warning that something was wrong, escaped with two nearby miners as the last men to leave the mine alive. As families waited anxiously, rescue crews from as far away as Butte and Cascade County worked around the clock to clear debris and search for survivors, but none were found. Some men were killed by a violent explosion, while most died from deadly methane gasses released by the blast. The disaster prompted state and national investigations that led to improvements in mine safety, and it is also remembered for the final message left by two trapped miners awaiting the poisonous gas: "Walter and Johnny. Good-bye/ Wives and daughters We died an easy death. Love from us both. Be good."