Ground zero
point on the Earth's surface closest to a detonation
Ground zero is the name for the exact place where an explosion occurs. It is the place where the most damage happens. The farther away from ground zero, the less damage there is. Sometimes, people say "ground zero" about a famous explosion, like the atomic bomb in Hiroshima or the September 11 attacks. These places can have special markers at ground zero.
![](http://up.wiki.x.io/wikipedia/commons/thumb/e/e3/HiroshimaGroundZeroMarker6952.jpg/220px-HiroshimaGroundZeroMarker6952.jpg)