Mt. Vesuvius in Italy and Mt. St. Helens in the United States are both famous
mountains. They are both volcanoes. A volcano is a mountain that is open at
the top. Smoke and hot air come out of the hole. Sometimes very hot rock also
comes out of the mountain. That can mean trouble for people nearby. This is
what happened with Mt. Vesuvius and Mt. St. Helen. Hot rock poured out of
Mt. Vesuvius and cover the town of Pompeii in 79 AD. Everyone in the town
was killed. The Mt. St. Helens volcano did not kill many people. There were
no cities close to the mountain. But the hot rock killed a large part of the
forest. And a lot of dirt fell on cities many miles away.