Pence prays with mourners in New York

Vice President Mike Pence spoke to a mournful crowd at the Tunnel to Towers Foundation ceremony, where he read the Bible's 23rd Psalm.

"For the families of the lost and friends they left behind, I pray these ancient words will comfort your heart and others," said the vice president, drawing applause from the crowd of hundreds.

The ceremony separate and away from the site of the World Trade Center honored the memories of the nearly 3,000 people killed in New York, at the Pentagon in Washington and near Shanksville, Pennsylvania on Sept. 11, 2001 — shaping American policy, perceptions of safety and daily life in places from airports to office buildings.