美国人民纪念2001年9月11日

This is What’s Trending Today.

On the morning of September 11, 2001, terrorists connected to al-Qaida hijacked four passenger airplanes. They flew two of them into the World Trade Center, known as the “Twin Towers,” in New York City and another into the Pentagon building in Arlington, Virginia.

The Pentagon is the headquarters of the U.S. Department of Defense, across the Potomac River from Washington, D.C.

Just a few minutes later, passengers on the fourth airplane took control from hijackers and crashed their airplane into a field in Shanksville, Pennsylvania. The plane was thought to be heading for Washington.

The attacks killed more than 3,000 people.

On Monday morning, President Donald Trump led a moment of silence at the White House and spoke at a memorial service at the Pentagon.

WATCH: Taps is played at the White House to honor the fallen on the 16th anniv. of 9/11.

— NBC Nightly News (@NBCNightlyNews) September 11, 2017
At the memorial service, Trump said “the terrorists who attacked us thought they could incite fear and weaken our spirit…But America cannot be weakened.”

Vice President Mike Pence traveled to Shanksville in the state of Pennsylvania to attend a service there.

During the day, Twitter users wrote about September 11 using the hashtags #NeverForget and #September11. “World Trade Center” was also a trending topic.

Some people wrote about their own experiences that day. Others posted photos and videos of the memorials and memorial services.

A New York City police officer rang a bell where the Twin Towers once stood at 10:28 a.m. That is the time when one of the towers fell 16 years ago.

Moment of silence marks the collapse of the World Trade Center’s north tower in New York City 16 years ago today. pic.twitter.com/LMjMBxL4A3

— Fox News (@FoxNews) September 11, 2017
At the same time, sunlight brightened an atrium at the new World Trade Center. The building is designed to let a strip of light in at 10:28 a.m. each September 11. The feature is known as “The Oculus.”

The Oculus at the World Trade Center commemorated the 9/11 attacks with a light display, in which the building's skylights were removed

— TIME (@TIME) September 11, 2017
At the memorial, family members of the victims read their names out loud.

WATCH: The name of each 9/11 victim is now being read at 9/11 Memorial in NYC to mark 16th anniv. of attacks.

— NBC Nightly News (@NBCNightlyNews) September 11, 2017
Sara Clarke is a journalist in Washington, D.C. She posted a photo of the memorial in Shanksville. She was in Pennsylvania on September 11 last year.

On 9/11 last year, I visited the #Flight93 memorial. Thinking about those families - and all who lost loved ones - today. #NeverForget pic.twitter.com/DaszOVcS6n

— Sara Clarke (@seclarke) September 11, 2017
Recent U.S. Presidents Barack Obama, George W. Bush and Bill Clinton all used Twitter to recognize the anniversary of the attacks.

Bush called for remembering “lives stolen,” Clinton called the rescue workers who helped save many lives that day “heroic” and Obama wrote: “No act of terror will ever change who we are.”

"Remembering the lives stolen on 9/11 and reflecting on the lessons of that day with @laurawbush." President George W. Bush #NeverForget pic.twitter.com/RNKogI85VJ

— TheBushCenter (@TheBushCenter) September 11, 2017
We are united in remembering those we lost, their families, and the heroic first responders in NY, VA, PA, and across America. #September11

— Bill Clinton (@BillClinton) September 11, 2017
We remember everyone we lost on 9/11 and honor all who defend our country and our ideals. No act of terror will ever change who we are.

— Barack Obama (@BarackObama) September 11, 2017
And that’s What’s Trending Today.

I’m Dan Friedell.

Dan Friedell wrote this story for VOA Learning English based on reports by hxen.net and the Associated Press. Mario Ritter was the editor.

How do you remember September 11, 2001? We want to know. Write to us in the Comments Section or on our www.hxen.net .