Thomas Langer said his brother, Timmy, "drank himself to death" over the grief of losing his wife, Vanessa, and their unborn child on september 11.
Thousands of survivors, victims' relatives, rescuers and others gathered on a misty Tuesday at the memorial plaza in NY where the World Trade Centre's twin towers once stood.
Members of the U.N. Security Council stood for a moment of silence led by U.S. Ambassador Nikki Haley.
Retired New York City firefighter Bruce Stanley holds a portrait of his late friend Liam Smith Jr., a New York City firefighter who died in the 9/11 attacks, during a commemoration ceremony for the victims of the September 11 terrorist attacks at the National September 11 Memorial, September 11, 2018 in New York City.
Subsequently, the names of those who lost their lives in the attack were read aloud.
The president and first lady Melania Trump planned to join an observance at the September 11 memorial in a field near Shanksville, Pennsylvania, where a new "Tower of Voices" was dedicated Saturday.
"Last year, President Trump signed the largest increase in our national defense in a generation", Pence said.
Further acts of tribute are slated to take place throughout the day, including the "Tribute in Light". "Let's not trivialize them". Their names will be recited at the World Trade Center Memorial Plaza.
It was a message of defiance in the face of terrorism, delivered by a New Yorker president who has at times struggled to adopt the role of consoler in chief.
In remembrance, Trump also posted "17 years since September 11th!"
"I get very anxious for the state of society". That number includes the hundreds of first responders who were killed trying to rescue those who were in the World Trade Center when the towers were struck and collapsed.
The Shanksville ceremony will include the sounds of the Tower of Voices, a 93-foot-tall concrete and steel structure featuring a wind chime for each person on board with its own distinctive sound.
The 9/11 Victims' Compensation Fund has paid out $US4bn to fund medical expenses for survivors of the terror attacks.
Trump had been in his Trump Tower penthouse, four miles (6.5 kilometres) from the World Change Center, all the plan by the 2001 attacks.
Powerful symbol that reminds us just how much this city has been bruised: a subway station that had been destroyed and buried under the debris, has re-opened its doors this weekend, 17 years after the tragedy.
Victims' families, too, have evolved and grown.
"They were not passive".