When survivors near Lake Nyos woke on the morning of 22 August 1986, the cattle were dead in the fields, the birds had fallen out of the trees, and 1,746 of their neighbours were lying where they had stood the night before, with no fire, no flood, and no wound to explain it. (opens in new tab)

Just before 10 p.m. on 21 August 1986, a low rumble rolled across the hills above Lake Nyos in northwestern Cameroon, loud enough that survivors later described it as thunder in the distance. A white mist rose off the water of the crater lake, slid down the valley walls under its own weight, and poured […]