New York City is marking 20 years since the Sept. 11 attacks with events across the city to memorialize those killed and remember the heroism of first responders and other citizens who helped bring people to safety that day. 

Mayor Bill de Blasio said at a security briefing Friday that New Yorkers should expect a heightened security presence across the city, including police and law enforcement personnel with long guns and with bomb detection equipment, even though there are “no specific and credible threats” facing the city currently. 

“You’re gonna see presence all over the city,” de Blasio said. “We do not consider Ground Zero as the only potential target tomorrow. We are going to protect the entire city.”

Police Commissioner Dermot Shea did not specify security measures, but said that there would be thousands of NYPD and federal officers on patrol. 

“I absolutely guarantee the safety of the city tomorrow,” Shea said. 

Here is a list of some of the events.

The National Sept. 11 Memorial and Museum Commemoration Ceremony

The memorial ceremony, reserved in person for families of victims of the Sept. 11 attacks and the 1993 World Trade Center bombing, begins with a citywide moment of silence at 8:46 a.m., the time the first plane hit the North Tower, followed by a reading of the names of the nearly 3,000 who died in the attacks.

Many elected officials, including President Joe Biden, are in attendance. The ceremony will have five other moments of silence before concluding around 12:30 p.m. 

9:03 a.m., when Flight 175 struck the South Tower

9:37 a.m., when Flight 77 struck the Pentagon, outside Washington, D.C.

9:59 a.m., when the South Tower fell

10:03 a.m., when Flight 93 crashed near Shanksville, Penn.

10:28 a.m., when the North Tower fell. 

The memorial will open to the general public at 3 p.m. and close at 11 p.m. 

Tribute in Light

The towers of light saluting the locations of the fallen World Trade Center towers are returning this year, illuminating overnight on Sept. 10 and 11. 

The lights will go on at 7:11 p.m. each evening, and fade away at dawn the next morning. 

Staten Island Postcards 9/11 Memorial Ceremony

Like many memorial events, Staten Island’s reading of the names of borough residents who died on Sept. 11, 2001, as well as first responders who died of 9/11-related diseases, is returning in person this year. 

The event will take place at Borough Hall, in St. George, beginning at 6:30 p.m., and can be watched via livestream.  

Windows on the World

One Fair Wage, a nonprofit group that advocates for service industry workers, will hold a private memorial ceremony for employees of Windows on the World, the beloved restaurant that sat at the top of the World Trade Center, at 1:15 p.m.

The commemoration will bring together dozens of former Windows on the World workers for a special reunion, and include several speakers, including Sen. Kirsten Gillibrand and Lt. Gov. Brian Benjamin. 

Flight 93 National Memorial

At 9:45 a.m., the park commemorating the location where Flight 93 crashed outside of Shanksville, Penn., will hold a ceremony to remember those on the flight who helped overcome hijackers on board, and diverted the flight from crashing into the U.S. Capitol building. 

The official remembrance will begin at 9:45 a.m. with a reading of the names on board, after which family and friends of those on board will be able to walk to the crash site. Former President George W. Bush and former First Lady Laura Bush will attend the ceremony. 

The ceremony will be livestreamed at the park’s Facebook page. 

Subway Series

The Yankees will play the Mets at Citi Field Saturday in a special game commemorating the 9/11 anniversary. 

The game will start with an on-field ceremony honoring first responders at 7 p.m., with a performance from the honor guards of the NYPD, FDNY, DSNY and Port Authority Police Department. Both teams will wear hats of first responder agencies. 

The game will start with the first pitch thrown by 2001 Mets manager Bobby Valentine to 2001 Yankees manager Joe Torre. 

Juniper Valley Park

At 7 p.m. residents of Middle Village and nearby neighborhoods will meet by the flagpole in Juniper Valley Park for a candlelight vigil sponsored by the neighborhood’s 9/11 Vigil Committee.