The 1986 disaster was caused by a gas explosion in the lake that resulted in villages being abandoned.

On August 21, 1986, Lake Nyos, a crater lake yet unknown to the world, made history when an enormous amount of carbon dioxide gas that had accumulated in its confines, forced its way to the surface. The resulting explosion engulfed the inhabited hillsides and plains, killing over 1,700 people and 3,500 livestock in the surrounding villages of Nyos, Cha, Kam and Subum in Fungom Subdivision, Menchum Division in the North West Region (formerly North West Province). Reports estimated that over 15,000 people were displaced.

President Paul Biya reacted immediately by dispatching rescue and relief teams to the disaster zone. This was followed by a flow of international aid for survivors that included financial, material, medical and scientific assistance. Emergency disaster management operations were undertaken to resettle survivors and bury the dead. A high-level UNESCO summit on the Lake Nyos disaster was organised in Yaounde in March 1987 and one of the solutions proposed by scientists was to de-gas the lake.

In 2001, the first de-gassing tubes were installed to siphon water from bottom layers of the lake to the top, allowing carbon dioxide to leak in safe quantities. Two additional tubes that were installed in 2011 have reportedly reduced the gas quantity thereby raising hopes for the return of affected people. In effect, the Governor of the North West Region and head of the Lake Nyos Disaster Management Committee, Adolphe Lele Lafrique, in June 2013 re-echoed government’s commitment to see survivors re-locate to the Nyos area.