Aljazeera.com created an interactive chart titled “September 11: Counting the costs to America” online: “Economy: $278 billion
The economic cost of 9/11 was significant, and also difficult to measure.
Many of these items require proving a negative: How many people decided not to fly because of 9/11? How many fewer tourists visited New York? Several academic studies have explored these issues, though, and the figures presented here represent their best estimates.
The worst economic damage, of course, happened in New York City. Valuable office space was destroyed; neighbouring properties were damaged; tens of thousands of people were unable to work for days or weeks; and thousands of rescue workers could face long-term health problems.”
– Gregg Carlstrom, “Interactive: How much did 9/11 cost the US? The attacks, which cost perhaps $400,000 to execute, will cost the United States more than $5 trillion.,” Aljazeera.com, Sept. 1, 2011