On farms, manure storage facilities are used to store animal waste, which can then be used for fertilizer. Farmers or farm workers may need to enter the facilities to repair or maintain equipment, such as pumps and intake hoses. These confined spaces are often oxygen-deficient atmospheres and can contain toxic and/or explosive gases that create a dangerous environment. Deaths most often occur when a person without necessary life support equipment enters an unventilated manure pit and is overcome by toxic gases or a lack of oxygen. Tragically, these incidents sometimes develop into multiple fatalities when other poorly trained and equipped farm personnel attempt to rescue the initial victim and become victims as well. The average annual number of deaths related to entering manure storage facilities more than doubled between 1975-1984 and 1995-2004, from 1.6 deaths per year to 3.5, respectively (Beaver and Field, 2007).