The city on Tuesday marked 17 years since the September 11th attacks with an emotional ceremony in lower Manhattan, where those who lost loved ones read their names aloud.
Bells tolled and moments of silence were held marking the moments when the planes struck the Twin Towers and when they collapsed.
The ceremony also included moments of silence for the attacks on the Pentagon and Shanksville, Pennsylvania.
The NYPD honored the officers who perished by reading their names during roll call Tuesday morning at precincts throughout the five boroughs.
A special memorial was held at Engine 54 in Midtown where 15 members who raced to the Twin Towers site perished.
The annual Tribute in Light is illuminating over the city Tuesday night. Two beams meant to represent the Twin Towers will be lit until dawn. They can be seen for miles.
The tribute first debuted six months after the terror attacks in March 2002 and has continued on every September 11th since.
President Donald Trump and First Lady Melania Trump joined an observance at the Sept. 11 memorial in a field near Shanksville, Pennsylvania, where a new Tower of Voices was dedicated Saturday. Vice President Mike Pence attended a ceremony at the Pentagon.
Trump, a Republican and native New Yorker, took the occasion of last year's anniversary to issue a stern warning to extremists that "America cannot be intimidated."
Nearly 3,000 people died in the attacks on 9/11, when international terrorism hit home in a way it previously hadn't for many Americans. September 11th still shapes American policy, politics, and everyday experiences in places from airports to office buildings, even if it's less of a constant presence in the public consciousness after 17 years.
This year's anniversary comes as a heated midterm election cycle kicks into high gear. But there have long been some efforts to separate the solemn anniversary from politics.
The group 9/11 Day, which promotes volunteering on an anniversary that was declared a national day of service in 2009, routinely asks candidates not to campaign or run political ads for the day. Organizers of the Ground Zero ceremony allow politicians to attend, but they've been barred since 2011 from reading names or delivering remarks.
Memorials to 9/11 continue to grow at Shanksville, where the Tower of Voices will eventually include a wind chime for each of the 40 people killed there, and ground zero, where work is to begin soon on a pathway honoring rescue and recovery workers.
It will serve as a way to honor those who became sick or died from exposure to toxins released when the World Trade Center's Twin Towers collapsed. Researchers have documented elevated rates of respiratory ailments, post-traumatic stress disorder and other illnesses among people who spent time in the rubble.
About 38,500 people have applied to a compensation fund, and over $3.9 billion in claims have been approved.
Meanwhile, rebuilding continues. A subway station destroyed on 9/11 finally reopened Saturday. In June, doors opened at the 80-story 3 World Trade Center, one of several rebuilt office towers that have been constructed or planned at the site. A performing arts center is rising.
However, work was suspended in December on replacing a Greek Orthodox church crushed in the attacks; the project hit financial problems.