Although they are rare, “limnic eruptions” do occur around the world from time to time. Also known as “lake explosions”, limnic eruptions occur when carbon dioxide builds up in the bottom of a lake and suddenly reaches a tipping point — very much like a can of soda getting shaken then popped open. One of the most recent examples of this occurred when Lake Nyos in Cameroon exploded in 1986 which suffocated and killed 1700 people. That explosion gave scientists an enormous amount of information into how and why these explosions occur, which is why experts have been closely monitoring Lake Kivu on the border of Rwanda. The danger in this case is that there is also a build up of methane, which could lead to a massive fiery eruption if both gases are not released beforehand.