Before he was Translated to Canterbury, Dr Williams found himself in New York, and in Manhatten on September 11th 2001. Here is what he has to say about it
http://www.youtube.com/watch?v=lfqqAYUDu5U
Pope Benedict also has a specially prepared collect he wrote after visiting the site in 2008
"God of Peace, bring your peace to our violent world, peace in the hearts of all men and women, and peace amoung the nations of the Earth. Turn to your way of Love, those whose hearts and minds are consumed with hatred. Grant that those whose lives were spared may live so that the lives lost here may not have been lost in vain. Comfort and consol us, stengthen us in hope and give us the wisdom and courage to work tirelessly for a world where true peace and love reign amoung nations and in the hearts of all."
Pope John-Paul who held the Papacy at the time of 9/11 said "Even if the forces of darkness seem to prevail, those who believe in God, know that Evil and Death do not have the final say."