The second tower of the World Trade Center bursts into flames after being hit by a hijacked airplane in New York in this September 11, 2001 file photograph. Al Qaeda leader Osama bin Laden was killed in a firefight with U.S. forces in Pakistan on May 1, 2011, ending a nearly 10-year worldwide hunt for the mastermind of the Sept. 11 attacks. The Brooklyn bridge is seen in the foreground. REUTERS/Sara K. Schwittek/Files (UNITED STATES – Tags: POLITICS CIVIL UNREST)