Two presidential candidates - former Mayor Rudy Giuliani and Democratic Sen. Hillary Rodham Clinton - were expected to attend.
President Bush was to spend the day in Washington, starting with a private 7:30 a.m. prayer service at St. John's Episcopal Church and then holding a moment of silence on the South Lawn of the White House.
At the Pentagon, Secretary of Defense Robert Gates is scheduled to host an observance for loved ones of those who were killed when American Airlines Flight 77 crashed there.
At 9:45 a.m., Gov. Rendell was scheduled to speak and lay a wreath at a temporary memorial in Stonycreek Township, near Shanksville, Somerset County, for the passengers of United Airlines Flight 93 who died preventing an even deadlier tragedy.
Throughout Pennsylvania, state facilities will fly flags at half-staff.
In Philadelphia, about 100 prison guards, police and sheriff's officers were to leave as early as 7 a.m. on a 260-mile motorcycle ride to the Flight 93 memorial. They were heading out from the Curran-Fromhold Correctional Facility on State Road.
Also in the city, the Canadian Consulate was to host an 8 a.m. breakfast honoring Claude Elliott, a Newfoundland mayor whose city accommodated thousands of stranded air passengers on 9/11.
At 10 a.m., the Philadelphia Police Department was scheduled to unveil 45-square-foot sections for a huge memorial quilt that will include sections contributed by law enforcement agencies across the country.
At noon, the Loaves and Fish Theatre Company will present a reading and discussion of the play 9/11 - A Day in the Life of a People at the National Constitution Center.
Tonight, the Phillies will host a "September 11th Salute & Military Recognition Night" during the game against the Colorado Rockies at Citizens Bank Park.
In South Jersey, the 200 Club of Burlington County held a memorial breakfast and service at Trinity Episcopal Church in Moorestown.
At noon in Willingboro, a ceremony of remembrance and reflection was to be held at the flagpole of Lourdes Medical Center of Burlington County.
At 5 p.m. at McGuire Air Force Base, the 305th Air Mobility Wing will hold a special base retreat ceremony.
These are just some of the events planned across the region.
Contact Inquirer online editor Peter Mucha at 215-854-4342 or firstname.lastname@example.org.