President Barack Obama and former President George W. Bush will appear at dedication ceremonies of the Flight 93 National Memorial this weekend.
Bush will speak at today’s dedication, which also will be attended by Vice President Joe Biden.
Obama and his wife, Michelle, will visit on Sunday’s 10th anniversary of the terrorist attacks.
The National Park Service is expecting thousands of visitors over the weekend.
Also attending today’s event will be dignitaries including former first lady Laura Bush, Secretary of the Interior Ken Salazar, National Park Service Director Jon Jarvis, and Gov. Tom Corbett.
Sarah McLachlan -- known for such songs as “In the Arms of an Angel” and “I Will Remember You” -- will perform today.