Updated

Vice President Mike Pence will deliver remarks at the crash site of United Flight 93 in a Pennsylvania field as the country marks the 16th anniversary of the Sept. 11 terror attacks.

The Republican will speak Monday at the ceremony in Shanksville at the national memorial to the victims of Flight 93.

Four al-Qaeda hijackers crashed the plane on Sept. 11, 2001, after the passengers and crew fought to wrest control of the aircraft, preventing it from reaching Washington, D.C.

Thirty-three passengers and seven crew members died.

Pence will address the family and friends of the victims and thousands of citizens who also are expected to attend.

U.S. Secretary of the Interior Ryan Zinke also will speak at the ceremony.