Nearly 3,000 people were killed when al-Qaeda hijackers flew four passenger planes into the Twin Towers, the Pentagon and a field in southwestern Pennsylvania on September 11, 2001.
According to the 9/11 Memorial & Museum, here is an overview of the most important events, starting with the impact of the first plane into the North Tower.
8:46 am
Five hijackers fly American Airlines Flight 11 to floors 93 to 99 of the North Tower. The 76 passengers and 11 crew members on board and hundreds in the building die instantly. Hundreds of people are trapped above the 91st floor because all three emergency stairwells were destroyed by the crash.
8:50 am
Then President George W. Bush is informed of the plane crash in a Florida elementary school classroom. He and his advisers assume it was an accident.
8:59 am
The Port Authority orders the evacuation of both towers. One minute later, the entire World Trade Center complex is evacuated.
9:03 am
Five hijackers crash United Airlines Flight 175 into floors 77 to 85 of the South Tower. The 51 passengers and nine crew members on board the plane die, as do an unknown number of people in the building. Many are trapped in elevators or on floors above the impact zone. People jump to their deaths from the towers.
The death toll is currently estimated at between 50 and over 200.
The NYPD is calling for a second Level 4 mobilization.
9:05 am
President Bush learns that the second plane has crashed. Before leaving, he gives a one-minute address to the Florida public. At this point, it is a terrorism investigation.
9:37 am
Five hijackers fly American Airlines Flight 77 into the Pentagon. The 53 passengers and six crew members on board die. More than 100 military and civilian personnel on the ground also lose their lives.
9:59 am
The South Tower collapses within 10 seconds after burning for nearly an hour, killing more than 800 people who were in the building at the time.
10:03 am
Four hijackers crash Flight 93 in a field near the town of Shanksville, Pennsylvania, about 20 minutes’ flight from Washington, DC, after passengers and crew storm the cockpit. The 33 passengers and seven crew members on board die.
The Tri-State Complex is observing the 23rd anniversary of the September 11, 2001 attacks. NBC New York is presenting a special report with coverage of the ceremonies in Lower Manhattan and the entire region.
10:15 am
Parts of the Pentagon collapse.
10:37 am
The North Tower collapses. Over 1,600 people are killed in the attack on the building.
11:02 am
The then New York Mayor Rudy Giuliani calls for the evacuation of Lower Manhattan.
Early afternoon
Rescue efforts at the World Trade Center site, now known as Ground Zero, continue.
A photographer took a photo of Edward Fine walking away from the Twin Towers, covered in dust and debris, with a cloth over his mouth.
17:20
7 The World Trade Center collapses after burning for hours. It had been evacuated long before.
20:30
Bush addresses the nation from the White House.
“The search for those behind these evil acts is ongoing,” he says. “I have deployed all the resources of our intelligence and law enforcement agencies to find those responsible and bring them to justice. We will make no distinction between the terrorists who committed these acts and those who harbor them.”
