AFP OUT) U.S. President Barack Obama and first lady Michelle Obama make a stop at Section 60 to mark the eleventh anniversary of the 9/11 terrorist attacks on September 11, 2012 at Arlington National Cemetery in Arlington, Virginia. The nation is commemorating the eleventh anniversary of the September 11, 2001 attacks which resulted in the deaths of nearly 3,000 people after two hijacked planes crashed into the World Trade Center, one into the Pentagon in Arlington, Virginia and one crash landed in Shanksville, Pennsylvania.