Wednesday marks the 36th anniversary of the deadliest volcanic event in U.S. history: the eruption of Mount St. Helens, which killed every living thing in a 230 mile radius. But the slopes around the volcano are now beginning to repopulate with plant and animal life, giving biologists a unique opportunity to watch an ecosystem develop in real time. Science correspondent Miles O’Brien reports.

Source: From Mt. St. Helens’ volcanic ashes, Mother Nature rebuilds