The Lake That Killed 1,700 People Without Warning

On August 21, 1986, a silent and invisible cloud swept through the valleys around Lake Nyos in Cameroon. There was no lava. No fire. No visible poison. Yet by morning, more than 1,700 people had died. The cause was a massive release of carbon dioxide that had been trapped deep beneath the lake for years. In this documentary, we explore how the gas accumulated, why the disaster happened so suddenly, what scientists discovered afterward, and how engineers later developed a system to prevent another catastrophe. We also look at Lake Monoun, the unanswered question of what exactly triggered the Lake Nyos disaster, and why scientists continue to monitor other gas-rich lakes such as Lake Kivu. This is the story of one of the strangest natural disasters ever recorded. This is Discoverium. Discover the extraordinary. 00:00 The Lake That Killed 1,700 People Without Warning 01:29 Where Is Lake Nyos? 02:58 A Peaceful Lake Hiding Something Below 04:25 How Carbon Dioxide Built Up in the Deep Water 05:56 August 21, 1986 07:23 The Invisible Cloud 08:53 Why People Had Almost No Warning 10:16 What Investigators Found 11:54 What Triggered the Disaster? 13:35 Lake Monoun: The Warning Two Years Earlier 15:02 Could It Happen Again? 16:37 The Pipes That Keep the Lake Safe 18:15 Other Dangerous Lakes 19:39 The Danger You Cannot See