ground zero

Some of the construction details (reinforcing rod splices, for example) [in Hiroshima and Nagasaki, Japan] were often poor, and much of the concrete was definitely weak; thus some reinforced concrete buildings collapsed and suffered structural damage when within 2,000 feet of ground zero, and some internal wall paneling was demolished even up to 3,800 feet.

"This is ground zero," she said. "If regulators don't adopt a zero tolerance for violations of standards then what we will have are places that are going to have unacceptable environmental damage."

James Meredith's forced admission was a milestone in upending the old order in America's most segregated state, a kind of race relations ground zero.