World leaders send their condolences on 20th anniversary
Leaders from around the world shared their reflections and condolences on the 20th anniversary of the Sept. 11 attacks.
Queen Elizabeth said in a statement she was still moved by the unity shown by the world during such a tragic time.
"It reminds me that as we honour those from many nations, faiths and backgrounds who lost their lives, we also pay tribute to the resilience and determination of the communities who joined together to rebuild," she said in a statement.
The U.S. national anthem played at the changing of the guard at Windsor Castle.
Ursula von der Leyen, the president of the European Union Commission, tweeted, "The EU stands with the USA in defending freedom & compassion over hate."
UN Secretary General Antonio Guterres issued a statement honoring first responders and that his "thoughts are with the victims and their families."
-ABC News' Guy Davies