Celebrities have been paying tribute to those who lost their lives on September 11, 2001, on the 15th anniversary of the terrorist attacks.
Stars including Victoria Beckham, Lady Gaga and Ryan Seacrest have all posted messages on Twitter.
Many have tweeted under the hashtag #NeverForget.
Nearly 3,000 people were killed when passenger jets hijacked by al Qaida terrorists struck the twin towers of the World Trade Centre in New York and the Pentagon outside Washington.
A fourth hijacked plane crashed into a field in Pennsylvania.