An American flag is lowered at the Pentagon in Washington, Saturday, Sept. 11, 2021, at sunrise on the morning of the 20th anniversary of the terrorist attacks.
Former President Barack Obama, former First Lady Michelle Obama, President Joe Biden, and First Lady Dr. Jill Biden, attend the ceremony to remember the victims of the attacks.
Kathy Birch stands next to her brother's name, Charles Gregory "Chuck" Costello Jr, who was an elevator electrician who ran into Tower 1 of the World Trade Center before the collapse.
A visitor captures the flowers and American flags at the south pool resting among the tributes those who died at the National September 11 Memorial & Museum.
Military personnel visit the memorial at the north pool at the National September 11 Memorial & Museum.
Retired firefighter Darrell Sales and cyclist Jeremy Provancher pose with the south pool holding an American flag after completing their "Bay to Brooklyn" bicycle ride.
An American flag with an image of Jill Maurer-Campbell, one of the victims of the attack, as the visitor stands beside her name on the south pool at the National September 11 Memorial & Museum.