The many dangers to miners working underground included: rock falling from the roof or upper walls of the mine shaft, accidents with explosives, and health problems caused by the fine rock dust produced by the compressed-air jack hammers.  The jackhammers were given the name “widow-makers” because many miners died from silicosis, a lung disease caused by breathing the dust particles. Noxious gases such as carbon monoxide, nitrogen dioxide, and hydrogen sulphide, produced by incomplete combustion of the explosives, permanently damaged eyes or lungs and even caused death.