After 9/11, who came up with the expression "Ground Zero" ?

The expression has been around for much longer than 9/11. It originated in 1946 and referred to the spot where atomic blasts occurred.

The "Red Zone" term is used to define the larger area of the incident. ( Where the accident took place). That area is large and unfocused. The trains were moving so the area is not defined. The term "Ground Zero" was actually created during WWII. The exact point where the first atomic bomb was set off. "Ground Zero" has been used since to describe several incidents that took place in our history. 1. World Trade Center. 2. The Chernobyl Disaster. 3. Both atomic blasts at the end of WWII. 4. Three Mile Island Nuclear Plant.

Ground Zero is still the official designation for the centre of a large explosion. Red zone is an area of danger.

Where the atomic bomb hits is called ground zero. the epicenter of any explosive disaster is called that.