U.S. Democratic presidential candidate Hillary Clinton leaves ceremonies marking the 15th anniversary of the September 11 attacks at the National 9/11 Memorial in New York, New York, United States September 11, 2016. REUTERS/Brian Snyder

U.S. Democratic presidential candidate Hillary Clinton leaves ceremonies marking the 15th anniversary of the September 11 attacks at the National 9/11 Memorial in New York, New York, United States September 11, 2016. REUTERS/Brian Snyder

U.S. Democratic presidential candidate Hillary Clinton leaves ceremonies marking the 15th anniversary of the September 11 attacks at the National 9/11 Memorial in New York, New York, United States September 11, 2016. REUTERS/Brian Snyder

September 12, 2016 12:38 AM (UTC+8)