PITTSBURGH — The 20-year anniversary of the day Flight 93 was forced down by brave passengers and crew — thwarting yet another deadly terrorist attack on Sept. 11, 2001 — will once again bring the "eyes of the world" back to Somerset County, a family member of one of the passengers said Wednesday.

Gordon Felt, whose brother was one of the 40 on Flight 93 who mounted an offensive against hijackers, said Saturday's anniversary will serve as a reminder to the nation that what happened 20 years ago on that flight shows everyday people can join together to do extraordinary things.

"The impact they've had on our history is immeasurable," Felt said of the passengers and crew, whose lives will be honored Saturday at the Flight 93 Memorial near Shanksville.

Memorial officials said more than 450 family members are expected to attend Saturday morning's annual observance ceremony, which this year will take on special significance with a speech from former President George W. Bush.

Flight 93 Memorial Superintendent Steve Clark said it's a "tremendous honor" that Bush and former First Lady Laura Bush will commemorate the 20-year mark at their memorial, as Bush was president when Sept. 11 happened.

It was Bush who signed the bill creating the memorial, officials noted.

"His dedication to this memorial has never wavered," said Felt, president of the Families of Flight 93. "We are honored that he'll be back, just as we're honored that [President Joe Biden] and [Vice President Kamala Harris] will be here this year."

Harris is scheduled to attend the observance ceremony. Biden will visit later in the day, officials said. Last year, when he was running for president, he placed a wreath of white flowers at the memorial and met with families.

In a scheduling release, the White House said Biden and first lady Jill Biden will "honor and memorialize the lives lost 20 years ago with travel to all three sites of the 9/11 attacks: New York City, New York, Shanksville, Pennsylvania and the Pentagon in Arlington, Virginia."

The observance ceremony — closed to the public and limited to family members and invited guests, but livestreamed on the memorial's Facebook page — will begin at 9:45 a.m. on Saturday. To mark the moment when Flight 93 crashed at 10:03 a.m., officials will read the names of the passengers and crew members and ring the Bells of Remembrance.

Also set to speak at the ceremony are Pennsylvania Gov. Tom Wolf and U.S. Secretary of the Interior Deb Haaland, among others. The United States Marine Band will provide music.

Former President Donald Trump spoke at last year's ceremony, recalling the chronology of events on Flight 93, commemorating the passengers and crew and praising the American people for banding together in the aftermath.

Clark, tasked with introducing Bush, said the goal of his opening will be to "bring the American people back to that moment when [the former president] was on the rubble in New York City with a bullhorn, talking to firefighters and really inspiring the nation through his eyes and through his leadership."

A variety of events to mark the day are also planned in the Pittsburgh area.

Members of the Pine-Richland/Mars Area U.S. Air Force JROTC, along with other others, will plant American flags, one for each person who died in the Sept. 11 attacks, along Route 228 in front of Mars Area High School. The flags will remain on display through Saturday, Sept. 11.

The Seneca Valley Junior Reserve Officers' Training Corps cadets will read remarks about the attacks and hold a moment of silence while retiring the colors to half-staff at 8:40 a.m. at the secondary campus, 128 Seneca School Road. Activities are also planned at the district's middle schools.

Mt. Lebanon High School will hold an assembly Friday morning with several guests, including Mt. Lebanon graduate Katy Phillips, who will be speaking "on the theme of everyday heroism based on her experiences working in the World Trade Center Complex and navigating NYC living in the aftermath of the attack."

The municipality of Mt. Lebanon will hold a program at 8:25 a.m. Saturday at the public safety center on Washington Road. It is to feature speeches, music and a moment of silence and include a silent walk through nearby Mt. Lebanon Cemetery, which will have photos from Sept. 11.

The Cranberry Township Volunteer Fire Company will hold a ceremony Saturday morning including the playing of taps in front of the company's 9/11 Memorial outside the fire station on Route 19. The times will be marked when the planes hit the twin towers and the Pentagon and crashed in Somerset.