September 11 terrorist attacks: NY marks 18 years since 9/11 carnage

Watch: Live stream of 9/11 ceremony at NYC memorial

Ilhan Omar Changes Tune: 'September 11th Was an Attack on All of Us'

As New York City marks the 18th anniversary of the terrorist attacks on the World Trade Center on Sept. 11, 2001, the National September 11 Memorial and Museum will be live streaming the 9/11 commemoration ceremony Wednesday morning from Manhattan.

A crowd of victims' relatives assembled at ground zero, where the observance began Wednesday with a moment of silence and tolling bells at 8:46 a.m. - the moment when a hijacked plane slammed into the World Trade Center's north tower. Chundera Epps, a sister of 9/11 victim Christopher Epps, said at last year's ceremony at the World Trade Center. "I called them off when I learned that they had killed a great American soldier from Puerto Rico and 11 other innocent people".

This year marks the 18th anniversary of the coordinated terrorist attacks.

"There's smiles in between the tears that say we didn't do this journey on our own, that we were here for each other", she said. That we were here for each other. "We love you, we miss you and you will always be America's heroes", said one woman after reading out the names of her brother and cousin.

A flag hangs on the Pentagon before a ceremony in observance of the 18th anniversary of the September 11, 2011, attacks.

The moment of silence is traditionally observed at 9:37 a.m. - the exact time when a plane crashed into the Defense Department's headquarters on September 11, 2001, killing 184 people.

Free to visit, the memorial site will host the Eighteenth Anniversary Observance on Wednesday beginning at 9:45 a.m. ET.

The commander in chief told families that "this is your anniversary of personal and permanent loss" and he said that their "loved ones will never ever be forgotten". The president placed a wreath of red, white and blue flowers at the memorial site.

Watch: Live stream of 9/11 ceremony at NYC memorial
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President Donald Trump is expected to join the memorial at the Pentagon, while Vice President Mike Pence is scheduled to speak at a ceremony in memory of Flight 93 near Shanksville, Pennsylvania. The effects are visible from airport security checkpoints to Afghanistan, where the post-9/11 U.S. invasion has become America's longest war. Trump had invited Afghan and Taliban leaders to Camp David, but abruptly announced via Twitter that he had canceled the previously-undisclosed summit.

A member of the U.S. Army Old Guard stands on the grounds of the National 9/11 Pentagon Memorial, in Washington, on September 11, 2019.

He will observe a moment of silence at 8:46 a.m., to mark when the first plane hit the North Tower of the World Trade Center, before delivering remarks to honor "the almost 3,000 lives that were tragically stolen from us on September 11, 2001", according to a White House spokesman.

The dead included Muslims, as Zaheda Rahman underscored after reading names at ground zero.

Joseph Henry says he was named after his uncle who was a firefighter, Joseph Patrick Henry. "I'm grateful that all of you are here today to hear it one more time".

Others made a point of spotlighting the suffering of firefighters, police and others who died or fell ill after exposure to the smoke and dust at ground zero. First responders will climb the equivalent of 110 flights of stairs to honor and remember the 403 firefighters and police officers killed in 9/11.

While research continues into whether those illnesses are tied to 9-11 toxins, a victims compensation fund for people with potentially September 11-related health problems has awarded more than $5.5-billion so far. More than 51,000 people have applied.

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