It’s a gas we all exhale and it helps plants grow. But it can also be a deadly gas. I’m referring to carbon dioxide and in an excerpt from John Richard Saylor’s book Lakes: Their Birth, Life, and Death (republished on Atlas Obscura), he explained how that gas caused the deaths of 1,746 people in the town of Nyos, Cameroon.
On the night of August 21, 1986, in Cameroon, Lake Nyos erupted. During that night, the lake, set in the crater of a dormant volcano, emitted not lava, not ash, not hot mud, but instead a massive cloud of cool carbon dioxide gas that silently raced down the slope, killing almost everything below. About a quarter of a cubic mile of carbon dioxide was released from Lake Nyos that night, traveling downhill at close to 45 miles an hour. In the nearby villages, 1,746 people died, most as they slept. In the town of Nyos itself, virtually every soul died.
Unlike many volcanic disasters, the Nyos event did not occur a thousand or even a hundred years ago. Occurring as it did in 1986, scientists were able to travel to the site within days. Accordingly, we have a detailed picture of what happened at Lake Nyos—one that is both terrifying and strange.
For the few survivors of the disaster, the situation they woke to must have extended beyond terror and into the horribly surreal. Some of the survivors did not wake for two days, and when they did, everyone around them had been killed—their families were dead and their neighbors were dead. Stumbling out of their houses, they could be forgiven for thinking that some otherworldly force had descended upon them and that the entire world had come to an end. Every living thing had died. Their chickens lay dead in the streets. Their livestock lay dead in the fields. The corpses of birds lay scattered randomly about. Even the insects were dead; rescue workers who arrived later noted the silence, the absence of insectile cacophony so common to equatorial Africa. It was not until days later that insect life reappeared, arriving at about the same time as the vultures that came from adjacent areas to feast on the bodies.
It’s a lengthy read, going into intricate detail of how and why this disaster occurred (although the exact nature of “how” is still uncertain).