Where is ground zero? Amy Westfeldt, Associated Press, Aug 26, 2010, Minneapolis-St. Paul StarTribune.
"The lines marking the site of the 2001 terror attacks change depending on whick New Yorker, family member and American you talk to. Even those who know it best can't agree on its boundaries.
Kathleen Hall Jamieson, Univ. Pennsylvania communications professor who studies political rhetoric says, "What you have is a classic instance of people responding to a symbol whose meaning is physically divorced from the actual space."

The map Artbrooks linked shows the outline of the area around ground zero closed off for safety reasons while heavy construction is ongoing.
It is as good as any as a reference. I will accept it. Don't know the dimensions of the NY blocks in this part of the island, etc. but can't see that critical measurements are important.