The disaster wich occurred in Tchigoma (a village located at about 25km from the city of Bulambika) in the chiefdom of Bunyakiri was investigated. The disaster caused the death of 3 people and some of them just survived. The accident was caused by the exposure to the high concentration of two gases during the digging of a toilet pit. The following concentrations were recorded in the hole considered as the epicenter: the carbon dioxide (CO2) at 93.8% and the carbon monoxide CO at 2031 parts per million, using GA2000 equipment. Although the exact value of the lethal concentration for humans is uncertain, these recorded values are too high for mammals’ survival .The mortality caused by these gases is a function of the inhaled concentration and duration of exposure. From the observations on the site, we had concluded that the gas were generated the peat covered by the alluvium layer considered as a roof.