This research demonstrated that water, because of its high heat extraction capability, was superior to other agents for extinguishing covered coal fires. The water must be delivered directly to the site of the burning, and the sparger technique proved to have limitations for this purpose. A single sparger tube can extinguish a swath of burning coal about 20 inches in width. Therefore, in a real fire situation one sparger tube would have to be inserted into a covered fire for every 20 inches of entry width. This restriction on the sparger method might be eliminated by the use of high-pressure water jets. It has been demonstrated that jets of water that are delivered at pressures of about 4,000 psi can penetrate coal to a depth of several feet. Accordingly, further research to evaluate the feasibility of high-pressure spargers for quenching covered coal fires should be considered. This recommendation, however, must be considered in light of other practical conditions that exist in entries, such as unavailability of high-pressure water supply.