How Many People Died in 9/11? Twin Towers Facts

On the morning of September 11, 2001, the deadliest terrorist attack ever carried out on American soil killed 2,977 people. Nineteen terrorists associated with al-Qaeda hijacked four commercial airplanes and turned them into weapons, flying two into the Twin Towers of the World Trade Center in New York City, a third into the Pentagon outside Washington, D.C., and a fourth into a rural field in Pennsylvania. More than two decades later, the question "how many people died in 9/11?" remains one of the most searched facts about that day — and the answer is tied to a detailed count of victims across four crash sites, the collapse of two iconic skyscrapers, and the largest single-day loss of emergency responders in U.S. history.

What Happened on the Morning of September 11, 2001?

On September 11, 2001, nineteen terrorists associated with al-Qaeda, an Islamist extremist group founded by Osama bin Laden, hijacked four commercial airplanes scheduled to fly from the East Coast to California, according to the 9/11 Memorial & Museum. In a coordinated attack that turned the planes into weapons, the hijackers deliberately flew American Airlines Flight 11 into the North Tower of the World Trade Center at 8:46 a.m. ET and United Airlines Flight 175 into the South Tower at 9:03 a.m. ET.

At 9:37 a.m., a third plane, American Airlines Flight 77, crashed into the Pentagon in Arlington, Virginia — the headquarters of the U.S. Department of Defense. The fourth aircraft, United Airlines Flight 93, crashed into a field near Shanksville, Pennsylvania, at 10:03 a.m. after passengers and crew members, having learned of the earlier attacks through phone calls to the ground, fought back against the hijackers and likely prevented an attack on the U.S. Capitol or the White House.

How Many People Died in the 9/11 Attacks?

A total of 2,996 people were killed in the 9/11 attacks, including the 19 hijackers aboard the four airplanes, according to HISTORY.com. Excluding the hijackers, 2,977 people lost their lives — the figure the 9/11 Memorial & Museum cites as the single largest loss of life resulting from a foreign attack on American soil. The victims included citizens of more than 90 countries.

The death toll broke down across three locations:

• World Trade Center (New York City): 2,753 people were killed, including 343 FDNY firefighters, 23 New York City police officers, and 37 Port Authority police officers who were working to evacuate the buildings and rescue office workers trapped on higher floors.
• The Pentagon (Arlington, Virginia): 184 people were killed, including 59 aboard American Airlines Flight 77 (some counts list 189 when the five hijackers are included).
• Shanksville (Pennsylvania): 40 passengers and crew members were killed aboard United Airlines Flight 93 (44 total, including the four hijackers).

Overall, the attacks caused the deaths of 441 first responders, the greatest loss of emergency responders in a single day in American history.

The Twin Towers: What They Were and Why They Fell

The Twin Towers — officially One World Trade Center (the North Tower) and Two World Trade Center (the South Tower) — were the centerpiece of a seven-building complex in Lower Manhattan. Each stood 110 stories tall, and for a brief period after their completion in the early 1970s they were the tallest buildings in the world.

The towers collapsed because the impact of the planes and the intense fires that followed — fueled by thousands of gallons of jet fuel — severely weakened the buildings' structural steel, which had been built to withstand winds in excess of 200 mph. The South Tower, struck second, collapsed first at 9:59 a.m., just 56 minutes after impact. The North Tower collapsed at 10:28 a.m., 102 minutes after being struck. Only 16 people who were inside the towers at the time of the collapses survived; almost 10,000 others were treated for injuries, many of them severe.

Timeline: How the Attacks Unfolded

The attacks happened in under two hours, but the sequence of events remains one of the most studied timelines in modern history:

• 8:46 a.m. — American Airlines Flight 11 crashes into the North Tower.
• 9:03 a.m. — United Airlines Flight 175 crashes into the South Tower.
• 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 and crew fight back.
• 10:28 a.m. — The North Tower collapses.

Who Was Responsible and How Did the U.S. Respond?

The attacks were orchestrated by al-Qaeda and its leader, Osama bin Laden. In a televised address that evening, President George W. Bush declared that the United States would "make no distinction between the terrorists who committed these acts and those who harbor them." Operation Enduring Freedom, the U.S.-led international effort to oust the Taliban regime in Afghanistan and dismantle al-Qaeda's network there, began on October 7, 2001.

In the wake of the attacks, the Homeland Security Act of 2002 created the Department of Homeland Security, and the bipartisan 9/11 Commission later identified Khalid Sheikh Mohammed as "the principal architect of the 9/11 attacks" in its report released on July 22, 2004. Osama bin Laden remained at large until May 2, 2011, when he was killed by U.S. forces in Abbottabad, Pakistan. The last U.S. military forces left Afghanistan on August 30, 2021.

Remembering 9/11 Today

Today the National September 11 Memorial & Museum stands at the World Trade Center site in Lower Manhattan. The winning memorial design, "Reflecting Absence" by Michael Arad, features two reflecting pools set within the footprints of the original Twin Towers. The names of all 2,977 victims are engraved on 152 bronze panels surrounding the pools, arranged so that colleagues, friends, and people on the same flight are memorialized together. The 9/11 Memorial opened on September 11, 2011, the Museum opened in May 2014, and One World Trade Center opened in November 2014. Each year, the "Tribute in Light" — two beams visible from more than 60 miles away — honors those who were lost.

Key Takeaways: 9/11 Facts at a Glance

• 2,977 people were killed in the attacks (2,996 including the 19 hijackers).
• 2,753 died at the World Trade Center, 184 at the Pentagon, and 40 in Shanksville, Pennsylvania.
• 441 first responders died, including 343 FDNY firefighters, 23 NYPD officers, and 37 Port Authority officers.
• Nineteen al-Qaeda terrorists hijacked four planes; passengers aboard Flight 93 fought back, and the plane crashed in a Pennsylvania field.
• The Twin Towers collapsed because fires weakened their structural steel — the South Tower at 9:59 a.m. and the North Tower at 10:28 a.m.