This Sunday marks the 21st anniversary of the September 11th attacks on the World Trade Center and the Pentagon, and the crash of United Airlines Flight 93. 

Here are some of the events taking place this weekend to honor the nearly 3,000 lives lost in the tragedy.

9/11 Memorial & Museum Anniversary Commemoration Ceremony

The annual event at the site of the World Trade Center off West and Vesey streets takes place this Sunday beginning at 8:40 a.m. The ceremony is expected to end at noon. Vice President Kamala Harris and Second Gentleman Douglas Emhoff are expected to attend.

The ceremony traditionally includes a reading of the victims’ names, as well as moments of silence at the points when the planes struck both towers, when American Airlines Flight 77 struck the Pentagon, when United Airlines Flight 93 crashed near Shanksville, Pennsylvania, and when both towers collapsed. 

Access to the plaza is not open to the public during the ceremony. The museum will also be closed to the public throughout the day, open only for the families of 9/11 victims. 

At 3 p.m, the Memorial Plaza opens to the public, where people can view the Tribute in Light, which will remain lit until midnight.

Tribute in Light

From dusk to dawn on Sunday night, twin beams symbolizing the World Trade Center towers will light up the city’s skyline.

The beams reach up to four miles in the sky and are positioned into two 48-foot squares, representing the shape and orientation of the Twin Towers.

The tribute can be seen from a 60-mile radius around lower Manhattan.

Various landmarks throughout the city, including the Empire State Building, One World Trade Center, the LIRR East End Gateway at Penn Station and the Kosciuszko Bridge, will also light up in blue that evening to mark the anniversary of the attacks.

NYC Fire Museum Memorial Service

The NYC Fire Museum at 278 Spring Street commemorates the 21st anniversary of 9/11 with a wreath-laying ceremony at 11 a.m. It will take place in the museum’s permanent memorial dedicated to the 343 FDNY members who lost their lives on 9/11.

The museum also features a new exhibition, One Day in September, recognizing the courageous efforts of first responders on 9/11 through a portrait series, personal artifacts, and short interviews with first responders’ family members. The exhibition is on view until Oct. 2, 2022.

The museum will also be open and free of charge from 10 a.m. to 5 p.m. on Sunday.

Staten Island Postcards Memorial Ceremony

The annual memorial on Staten Island takes place Sunday evening at 6:30 p.m and is held at the Postcards Memorial site in St. George, which honors the 274 Staten Island residents who lost their lives in the 9/11 attacks. 

Borough President Vito Fossella hosts the ceremony, which will feature the recitation of the names of Staten Islanders who lost their lives on 9/11. It also honors first responders who have since died due to illnesses stemming from their work at the World Trade Center site. 

Interfaith Prayer and Peace Vigil 

A vigil will take place at the U.N. Public Plaza on Sunday starting at 2 p.m. It will include religious organizations and community groups of various faiths with the goal to “promote peace and unity between individuals of different faith groups,” according to the press release. The event will also feature art and performances.

The event is sponsored by the Muslim Community Network, Interfaith Center of New York, Kolot Chayeinu, African Life Center,and Congregation Beit Simchat Torah.

Tunnel to Towers 9/11 Prayer Service 

The Tunnel to Towers Foundation will host a prayer remembrance ceremony at the base of the America's Response Monument - located in Liberty Park, not far from the 9/11 Memorial & Museum - to honor the nearly 3,000 lives lost on 9/11. 

The foundation honors the life of FDNY Firefighter Stephen Siller, who died on 9/11 after he ran through the Brooklyn Battery Tunnel to the World Trade Center with 60 pounds of gear strapped to his back.

The ceremony begins at 7 a.m. on Sunday and will feature FDNY, NYPD and Port Authority Police Ceremonial Units, a Pipes & Drums processional, and a color guard.