Today is the 18th anniversary of the September 11th terror attacks.
Almost 3,000 people died on this day in 2001 in what was the worst act of terror on American soil.
Those killed at the World Trade Centre, Pentagon and aboard Flight 93 will be remembered in events across the US later.
The first Irish casualty to be recovered from the Twin Towers was Cappawhite man Martin Coughlan.
Social media users commemorating the anniversary are being encouraged to use the hash tag #Honor911.