Abstract: At around 1:50 p.m. on October 11, 1994, Employees #1 and #2 were working in an office building at a cooperative grain elevator facility. A pipeline, which was carrying liquid propane gas to the grain dryer on the elevator, and which passed underground near the main office building, had developed an undetected leak. The propane gas leached through the soil, which effectively removed the odor additive, and found its way into the office. When the concentration of the now odorless propane reached the flammable range, an explosion occurred. Employee #1 was killed and Employee #2 was hospitalized. Although the cooperative distributed propane for sale, a periodic leakage survey had not been conducted.