The commander-in-chief, who attended the event with his wife First Lady Melania Trump, said the bravery of those fallen heroes shows "free people are never at the mercy of evil".
Felt, whose brother Edward died aboard Flight 93, recalled that the passengers came together and developed a plan to confront the terrorists "in just 35 minutes", having learned that hijacked planes had already been flown into the two towers of the World Trade Center and the Pentagon.
Commemorating the 17th anniversary of the attacks that struck the World Trade Center in NY and the Pentagon in Washington, Trump said the nation shared the grief of the family members whose loved ones were lost that day.
A photo captured a fist-pumping President Donald Trump and first lady Melania Trump on Tuesday as they arrived in Pennsylvania to attend a memorial service on the anniversary of the 9/11 terror attacks.
The Trumps were on their way to a 9/11 Memorial Service in Shanksville, PA, and many people feel the tone-deaf gesture and strangely excited vibe the president gave off as he greeted assembled supporters was wildly inappropriate.
Hurricane Florence's path: Track the storm here
Forecasters have predicted as much as 20inches of rain in parts of North Carolina, which could cause potentially fatal flooding. Florence has maximum sustained winds of 105 miles per hour , though that number is likely to increase as the storm strengthens.
Meanwhile, Vice President Mike Pence is reportedly at the Pentagon, where a plane crashed directly into the building.
Trump observed the solemn anniversary for the first time as president past year.
Remembrance ceremonies were held around the nation Tuesday to honor the almost 3,000 people who died 17 years ago in the 9/11 terrorist attacks.
september 11 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. They said suspects in both attacks were inspired by the Islamic State extremist group.
Thousands of people will gather in New York City, Washington, DC and Shanksville, Pennsylvania.
WTA calls for equal treatment of players, on-court coaching
But just who is this 20-year-old? Are we not going to have coaching? "She wanted this moment, and she played like it". Her family moved to the United States when she was three, and she has dual Japanese and American citizenship.
A ceremony is being held in Shanksville, Pennsylvania Tuesday morning to commemorate the 17th anniversary of the September 11 attacks.
Sinodinos, who works near the trade center, said she tries not to let the recent attacks unnerve her. Researchers have documented elevated rates of respiratory ailments, post-traumatic stress disorder and other illnesses among people who spent time in the rubble.
In a sign of how devastating the attacks were to the Big Apple, the Cortlandt Street subway station - left for years under mountains of debris - only reopened on Saturday.
"You have to move on", she said.
Tropics erupt as Florence, Helene and Isaac all churn in the Atlantic
This enhanced satellite image made available by NOAA shows Tropical Storm Florence , centre, in the Atlantic Ocean on Saturday. Risky swells generated by Florence affected Bermuda and have begun to reach parts of the Eastern Seaboard.