Simplify the following text for a Grade 5 native English-speaking person.
Original: The term ground zero ( sometimes also known as surface zero as distinguished from zero point ) describes the point on the Earth 's surface closest to a detonation . In the case of an explosion above the ground , ground zero refers to the point on the ground directly below the detonation ( see hypocenter ) .
Simplified: Ground zero is the name for the exact place where an explosion occurs .