Bells tolled and heads were bowed in lower Manhattan, in remembrance of the 3,000 people who died in the September 11th terrorist attacks sixteen years ago.
Some of the victim's families held signs and others called out their loved ones' names at Ground Zero.
Memorial events like this have become tradition on this somber day, as family and friends remember those who died.
President Trump led the White House staff in a moment of silence at the exact time the first hijacked plane crashed into the World Trade Center's North Tower.
At sunrise, a giant American flag was unfurled and draped at the Pentagon to honor the 184 people who died there. The President placed a wreath on the memorial stone engraved with victims' names and promised that America would never forget.
Hundreds, including Vice President Pence, took part in a memorial service at the Flight 93 National Memorial near Shanksville, Pennsylvania.
Mourners honored the 40 brave passengers who died trying to retake the plane from hijackers.