Sept. 11: New monument celebrates passengers, crew of Flight 93 SHANKSVILLE, PA - SEPTEMBER 09: The Tower of Voices stands above visitors, dignitaries and family members of the victims of Flight 93 at the Flight 93 National Memorial on September 9, 2018 in Shanksville, Pennsylvania. (Photo by Jeff Swensen/Getty Images)Photo by: Jeff Swensen Sept. 11: New monument celebrates passengers, crew of Flight 93 SHANKSVILLE, PA - SEPTEMBER 09: Visitors, dignitaries and family members of the victims of Flight 93 listen under drenching rains at the dedication of the Tower of Voices at the Flight 93 National Memorial on September 9, 2018 in Shanksville, Pennsylvania. (Photo by Jeff Swensen/Getty Images)Photo by: Jeff Swensen Sept. 11: New monument celebrates passengers, crew of Flight 93 SHANKSVILLE, PA - SEPTEMBER 09: The Tower of Voices stands above visitors, dignitaries and family members of the victims of Flight 93 at the Flight 93 National Memorial on September 9, 2018 in Shanksville, Pennsylvania. (Photo by Jeff Swensen/Getty Images)Photo by: Jeff Swensen Sept. 11: New monument celebrates passengers, crew of Flight 93 SHANKSVILLE, PA - SEPTEMBER 09: The Tower of Voices stands above visitors, dignitaries and family members of the victims of Flight 93 at the Flight 93 National Memorial on September 9, 2018 in Shanksville, Pennsylvania. (Photo by Jeff Swensen/Getty Images)Photo by: Jeff Swensen Sept. 11: New monument celebrates passengers, crew of Flight 93 SHANKSVILLE, PA - SEPTEMBER 09: Visitors, dignitaries and family members of the victims of Flight 93 listen under drenching rains at the dedication of the Tower of Voices at the Flight 93 National Memorial on September 9, 2018 in Shanksville, Pennsylvania. (Photo by Jeff Swensen/Getty Images)Photo by: Jeff Swensen Sept. 11: New monument celebrates passengers, crew of Flight 93 SHANKSVILLE, PA - SEPTEMBER 09: Visitors, dignitaries and family members of the victims of Flight 93 listen under drenching rains at the dedication of the Tower of Voices at the Flight 93 National Memorial on September 9, 2018 in Shanksville, Pennsylvania. (Photo by Jeff Swensen/Getty Images)Photo by: Jeff Swensen Sept. 11: New monument celebrates passengers, crew of Flight 93 SHANKSVILLE, PA - SEPTEMBER 09: Visitors, dignitaries and family members of the victims of Flight 93 listen under drenching rains at the dedication of the Tower of Voices at the Flight 93 National Memorial on September 9, 2018 in Shanksville, Pennsylvania. (Photo by Jeff Swensen/Getty Images)Photo by: Jeff Swensen Sept. 11: New monument celebrates passengers, crew of Flight 93 SHANKSVILLE, PA - SEPTEMBER 09: Former Director of Homeland Security Tom Ridge, readies himself to pull a cord attached to the chimes at the newly-unveiled Tower of Voices at the Flight 93 National Memorial on September 9, 2018 in Shanksville, Pennsylvania. (Photo by Jeff Swensen/Getty Images)Photo by: Jeff Swensen Sept. 11: New monument celebrates passengers, crew of Flight 93 SHANKSVILLE, PA - SEPTEMBER 09: Visitors, dignitaries and family members of the victims of Flight 93 listen under drenching rains at the dedication of the Tower of Voices at the Flight 93 National Memorial on September 9, 2018 in Shanksville, Pennsylvania. (Photo by Jeff Swensen/Getty Images)Photo by: Jeff Swensen Sept. 11: New monument celebrates passengers, crew of Flight 93 SHANKSVILLE, PA - SEPTEMBER 09: Family members of the victims of Flight 93 pull cords attached to the chimes at the newly unveiled Tower of Voices at the Flight 93 National Memorial on September 9, 2018 in Shanksville, Pennsylvania. (Photo by Jeff Swensen/Getty Images)Photo by: Jeff Swensen Sept. 11: New monument celebrates passengers, crew of Flight 93 SHANKSVILLE, PA - SEPTEMBER 09: Family members of the victims of Flight 93, Calvin Wilson and Gordon Felt Jr., join former Director of Homeland Security Tom Ridge and architect Paul Murdoch as they pull cords attached to the chimes at the newly unveiled Tower of Voices at the Flight 93 National Memorial on September 9, 2018 in Shanksville, Pennsylvania. (Photo by Jeff Swensen/Getty Images)Photo by: Jeff Swensen Sept. 11: New monument celebrates passengers, crew of Flight 93 SHANKSVILLE, PA - SEPTEMBER 09: The Tower of Voices stands above visitors, dignitaries and family members of the victims of Flight 93 at the Flight 93 National Memorial on September 9, 2018 in Shanksville, Pennsylvania. (Photo by Jeff Swensen/Getty Images)Photo by: Jeff Swensen Sept. 11: New monument celebrates passengers, crew of Flight 93 SHANKSVILLE, PA - SEPTEMBER 09: Family members of the victims of Flight 93, Calvin Wilson and Gordon Felt Jr., join former Director of Homeland Security Tom Ridge and architect Paul Murdoch as they pull cords attached to the chimes at the newly unveiled Tower of Voices at the Flight 93 National Memorial on September 9, 2018 in Shanksville, Pennsylvania. (Photo by Jeff Swensen/Getty Images)Photo by: Jeff Swensen Sept. 11: New monument celebrates passengers, crew of Flight 93 SHANKSVILLE, PA - SEPTEMBER 09: The newly-unveiled Tower of Voices marks the 17th anniversary of the crash of Flight 93 at the Flight 93 National Memorial on September 9, 2018 in Shanksville, Pennsylvania. (Photo by Jeff Swensen/Getty Images)Photo by: Jeff Swensen Sept. 11: New monument celebrates passengers, crew of Flight 93 SHANKSVILLE, PA - SEPTEMBER 09: Family members of the victims of Flight 93, Calvin Wilson and Gordon Felt Jr., join former Director of Homeland Security Tom Ridge, left, as they pull cords attached to the chimes at the newly unveiled Tower of Voices at the Flight 93 National Memorial on September 9, 2018 in Shanksville, Pennsylvania. (Photo by Jeff Swensen/Getty Images)Photo by: Jeff Swensen