Two light beams shining into the night sky from the New York City skyline (© Drew Angerer/Getty Images)

The «Tribute in Light» on the 18th anniversary of the 9/11 terrorist attacks, September 11, 2019, in New York City (© Drew Angerer/Getty Images)

In the 20 years since the September 11, 2001, terrorist attacks, Americans have gathered on the anniversary to remember the nearly 3,000 people who died in New York, Virginia and Pennsylvania, as well as the first responders who put their lives on the line to save victims.

Here’s a glimpse at how first responders around the United States have commemorated their lost colleagues over the past two decades.

Police officers with hands crossed and heads bowed, one with dog on leash (© Brittany Murray/MediaNews Group/Long Beach Press-Telegram/Getty Images)
(© Brittany Murray/MediaNews Group/Long Beach Press-Telegram/Getty Images)

In Long Beach, California, city officials, firefighters, police personnel (pictured here) and members of the community observed a moment of silence on September 11, 2019.

Uniformed person holding edge of large American flag being flown from fire truck ladder (© Jacquelyn Martin/AP Images)
(© Jacquelyn Martin/AP Images)

The Patriot Flag — which honors the military, first responders and families of the victims of 9/11 — is raised on a fire truck ladder at Arlington National Cemetery in  Virginia in 2011. The flag flew in all 50 states over 50 weeks to mark the 10th anniversary of the attacks.

Left: Soldier holding tribute plaque with photos of fallen firefighter (© Drew Angerer/Getty Images). Right: Firefighter holding large photo of fallen firefighter (© Amr Alfiky /Getty Images)
Left: (© Drew Angerer/Getty Images). Right: (© Amr Alfiky /Getty Images)

At left, a soldier at the National September 11 Memorial & Museum in New York holds pictures of Ruben Correa, a firefighter who died during the attacks. The COVID-19 pandemic required the 2020 ceremony to follow strict health protocols.

At right, retired New York City firefighter Bruce Stanley holds a portrait of his friend Liam Smith Jr., a New York City firefighter who died in the 9/11 attacks. Stanley and other first responders commemorated 9/11 victims at the National September 11 Memorial on September 11, 2018.

People in various uniforms holding large American flag (© Paul Sancya/AP Images)
(© Paul Sancya/AP Images)

First responders hold the Patriot Flag during a ceremony in Joplin, Missouri, on the 10th anniversary of 9/11. The flag is now displayed at the National 9/11 Memorial & Museum in New York.

Firefighters in dress uniform lighting memorial candles (© Stephen M. Dowell/Orlando Sentinel/Tribune News Service/Getty Images)
(© Stephen M. Dowell/Orlando Sentinel/Tribune News Service/Getty Images)

During a 2019 September 11 remembrance ceremony in Orlando, Florida, fire and police honor guard members light candles to remember firefighters and law enforcement officers killed in the attacks.

Left: Firefighters at church service (© Rogelio V. Solis/AP Images). Middle: Marine holding bugle under his arm (© Robert Nickelsberg/Getty Images). Right: Men and women sitting in spaced chairs on grass at memorial service (© Leonard Ortiz/MediaNews Group/Orange County Register/Getty Images)
Left: (© Rogelio V. Solis/AP Images). Middle: (© Robert Nickelsberg/Getty Images). Right (© Leonard Ortiz/MediaNews Group/Orange County Register/Getty Images)

At left, fire chiefs Willie Robinson (left) and Freddie Stallings (right) sing during a worship service at St. Andrew’s Episcopal Cathedral in Jackson, Mississippi. The service commemorated 9/11 victims and first responders on September 11, 2013, the 12th anniversary of the attacks.

At center, a U.S. Marine honor guardsman holds a bugle during a September 11, 2020, memorial ceremony in Scranton, Pennsylvania. Two residents of the town died in the attacks.

At right, first responders, military service members, dignitaries and civilians gather outdoors at the Richard Nixon Presidential Library and Museum in Yorba Linda, California, on September 11, 2020.

Sailor walking past large red, white and blue flag commemorating United Flight 93 (© Matt Rourke)
(© Matt Rourke/AP Photo)

In Philadelphia, a sailor walks past a flag aboard the USS Somerset in 2014. The ship is named for the Pennsylvania county where Flight 93 crashed after it was hijacked September 11, 2001. It was the last of three vessels honoring the attacks’ victims and first responders. Two other ships, the USS New York and the USS Arlington, are named for the cities that were attacked.

Policeman saluting at large sunken memorial with engraved names in New York City (© David Handschuh/Getty Images)
(© David Handschuh/Getty Images)

New York City Police Officer Danny Shea, a military veteran, salutes at the North Pool of the 9/11 Memorial at the World Trade Center site on the 10th anniversary of the attacks.