In photos: Remembering the Sept. 11 attacks, 25 years later

A woman places flowers at the September 11 memorial plaza in Lower Manhattan ahead of a ceremony commemorating the 25th anniversary of the Sept. 11, 2001, attacks at the National September 11 Memorial in New York on Friday. Dave Sanders/New York Times via AP hide caption

Across the country, ceremonies are being held to honor the thousands killed in the Sept. 11, 2001 terror attacks, when commercial planes crashed into the World Trade Center's twin towers, the Pentagon, and a field in Shanksville, Pa.

See photos of 25th anniversary commemorations from New York, Arlington, Va., Austin, Texas, Chicago, St. Louis, and Shanksville, Pa. .

Members of the military and first responders watch as an American flag is unfurled on the side of the Pentagon to mark the 25th anniversary of the September 11th terrorist attacks on September 11, 2026 in Arlington, Va. Finn Gomez/Getty Images hide caption

Darlene Johnson and David Johnson, both of Florissant, Mo., look over one of the flags at the "Flags of Valor" installation on Thursday, Sept. 10, 2026, at Art Hill in Forest Park, St. Louis. Brian Munoz/St. Louis Public Radio hide caption

Former U.S. President Biden, former U.S. President George W. Bush, former New York City Mayor Michael Bloomberg, and Vice President Vance attend the 25th anniversary commemoration of the September 11, 2001 attacks at the National September 11 Memorial in New York on September 11, 2026. Angela Weiss/AFP via Getty Images hide caption

President Donald Trump, and first lady Melania Trump arrive at an observance ceremony on the 25th anniversary of the 9/11 attacks, Friday, Sept. 11, 2026, at the Pentagon. Mark Schiefelbein/AP hide caption

Matt Dunleavy and his daughter Ellie Dunleavy take part in a ceremony commemorating the 25th anniversary of the Sept. 11, 2001, attacks at the National September 11 Memorial in New York City on Friday. Jeenah Moon/Reuters Pool via AP hide caption