NEW YORK (AP) — NFL teams will commemorate the 15th anniversary of the Sept. 11 attacks with special tributes before Sunday's season openers.

Before each of the 13 games, video messages from President Barack Obama and his predecessor, George W. Bush, will be shown. Each club will have special guests on the field, including first responders, community volunteers, hometown heroes and military members, for pregame activities and the playing of the national anthem.

Vice President Joe Biden will join 120 first responders in holding the American flag during the anthem at Philadelphia. Bush will toss the coin in Dallas, accompanied on the field by Laura Bush and two NYPD officers who responded to the attacks.

All coaching staffs will be given 9/11 lapel pins, and a special 9/11 decal will be placed on players' helmets.

The salutes will be synchronized during afternoon games Sunday.