The Toba supereruption
The largest eruption of the last 2.5 million years
About 74,000 years ago a volcano on Sumatra blew itself apart, leaving a caldera some 100 km long that now holds Lake Toba. Its ash blanketed South Asia; the "volcanic winter" that followed was long thought to have nearly wiped out humanity, but finds in India and Africa show people came through it without catastrophe.