Silence drifted over a tearful crowd as Paul Simon performed his famous "The Sound of Silence" at Ground Zero on Sunday, the anniversary of the September 11th terrorist attacks.

At the site, Presidents Obama and Bush stood together, along with their wives, Michelle and Laura. Mr. Obama read from Psalm 46: "God is our refuge and strength." Mr. Bush received a cheer when he took the stage to read from a letter Abraham Lincoln wrote during the Civil War.

Survivors of the attacks and family members of those who died spoke.

Watch the video above to see the crowd's reaction to Simon & Garfunkel's "The Sound of Silence."