9/11 remembrance: what is 9/11 and why the day endures

When people search what is 9/11, they’re asking about the deadliest terror attack on U.S. soil—the September 11 attacks carried out on 9/11/01. Four commercial flights were hijacked; two struck the Twin Towers in NYC, one hit the Pentagon in Virginia, and one crashed in Pennsylvania after passengers fought back. The day changed global security, foreign policy, and how we commemorate public tragedy. This guide brings together the essential 9/11 timeline, practical ways of remembering 9/11, and where to find tributes and memorials on the 9/11 anniversary.

9/11 timeline: minute-by-minute on Sept 11, 2001

If you’re looking for the timeline of 9/11 or what happened on 9/11, these are the widely observed milestones (all times Eastern):

8:46 a.m. — American Airlines Flight 11 hits the North Tower (WTC 1). This moment anchors many 9/11 times ceremonies and the first 9/11 moment of silence.

9:03 a.m. — United Airlines Flight 175 strikes the South Tower (WTC 2).

9:37 a.m. — American Airlines Flight 77 crashes into the Pentagon.

9:59 a.m. — The South Tower collapses.

10:03 a.m. — United Airlines Flight 93 crashes near Shanksville, Pennsylvania, after passengers resist the hijackers.

10:28 a.m. — The North Tower collapses.

These are the core 9/11 times many communities read aloud each year as they remember 9/11 and reflect on the lives lost.

Remembering 9/11: traditions, tributes, and the moment of silence

Across the U.S., the 9/11 remembrance includes:

Moment of silence for 9 11 at 8:46 a.m. ET, with additional pauses at 9:03, 9:37, 9:59, 10:03, 10:28 to mirror the events in the 9/11 timeline.

Reading of names at the 9-11 Memorial in NYC, often called the twin towers memorial (officially, the National September 11 Memorial & Museum).

Flags flown at half-staff nationwide on the 9/11 anniversary/911 anniversary, and local 9/11 tribute events in schools, city halls, and places of worship.

Community service projects held under the banner of remembering 9/11—a way to honour victims, first responders, and families.

If you’ve searched is today 9/11, most observances fall on September 11th each year, with some communities marking the nearest weekday.

The memorials: NYC, the Pentagon, and Flight 93

New York City (WTC): The 9-11 memorial features twin reflecting pools set in the footprints of the towers, with the names of those killed. The museum documents what happened on 9/11, the response, and ongoing impact.

The Pentagon: The Pentagon Memorial in Arlington, Virginia, honours the 184 victims of the attack on the pentagon; illuminated benches align by age and flight path.

Shanksville, Pennsylvania: The Flight 93 National Memorial commemorates passengers and crew whose actions prevented another strike on Washington, D.C.

Together, these sites anchor national 9/11 remembrance and year-round education for visitors of all ages.

9/11 times & ceremonies: how to observe at home or school

Even if you’re far from the memorials, you can join a 9/11 tribute:

Pause at 8:46 a.m. ET for a 9/11 moment of silence, then again at the subsequent times to follow the timeline of 9/11.

Display the flag respectfully; many communities follow half-staff guidance on the 9/11 anniversary.

Share stories or lessons learned with young people who ask what happened on 9/11; pair remembrance with age-appropriate resources.

Attend a local vigil or civic ceremony; many cities stream 9/11 remembrance programs online.

Volunteer—turn remembrance into action through service.

FAQs: quick answers people search each year

What time was 9/11? There isn’t one single time; the day is marked by several key moments. The first impact was 8:46 a.m., followed by 9:03, 9:37, 9:59, 10:03, 10:28 ET in the standard 9/11 timeline.

What is 9/11? Shorthand for the September 11 attacks of sept 11 2001/sep 11, when four planes were hijacked; two hit the Twin Towers in NYC, one hit the Pentagon, and one crashed in Pennsylvania.

Is today 9/11? If you’re reading on 9/11 anniversary day, many institutions will host a 9/11 remembrance with a 9/11 moment of silence and local 9/11 tribute programming.

Where is the 9/11 memorial? The main 9/11 memorial/9 11 memorial is at the World Trade Center site in NYC; there are dedicated memorials at the pentagon and in Shanksville.

9/11 anniversary media & “9/11 times” coverage

Newsrooms often publish a 9/11 timeline explainer, a remembering 9/11 essay, and live coverage from the 9-11 memorial ceremonies. If you’re seeking 9/11 times, most broadcasts list the sequence above and cut to live feeds for each moment of silence for 9 11. Many communities host 9/11 tribute concerts, bell tolls, and school-based 911 remembrance projects.

Why we remember 9/11

To remember 9/11 is to honour the lives lost, the courage of first responders, and the resilience of communities. The 9/11 remembrance each year—through shared 9/11 times, the reading of names, lowered flag, and reflection at the twin towers memorial, the Pentagon, and Shanksville—keeps the story present for those who lived it and clear for those asking today, what happened on 9/11.