One of the overwhelming things on 11 September 2001, especially for the people of New York City, was the amount of information they were getting about what was happening - much of which was wrong.

Many struggled to cope as they were bombarded with the latest developments. The exact events of that day did not emerge until some time later, following a commission set up to investigate the attacks.

Here are the main events of that day:

6am

Lead hijacker flies to Boston

Ringleader Mohamed Atta - and another of the terrorists - fly to Logan International Airport in Boston to be in place to board another aircraft shortly after.

Mohamed Atta (R) and Abdulaziz al Omari (C) pass through airport security at Portland International Jetport in Maine on 9/11

Mohamed Atta (R) and Abdulaziz al Omari (C) pass through airport security at Portland International Jetport in Maine on 9/11

Atta, a 33-year-old Egyptian national, had travelled in June 2000 from Europe to the US, where he and the other hijack team leaders began pilot training. At various points in 2001, he met with some of the other hijackers after they arrived in the US.

6.30am

Bush emerges after overnight Florida stay

US President George W Bush goes for a jog around the Florida resort where he and his staff had stayed the night ahead of a school visit that day.

7.05-7.40am

Second hijack team checks in

Newark International Airport. File pic

Newark International Airport. File pic

The second hijacking team arrive at Newark International Airport in New Jersey and begin to check in for United Airlines Flight 93 before starting to board.

7.15am

Third hijack team arrives at airport

Dulles Airport. File pic

Dulles Airport. File pic

The third team arrive at Washington Dulles Airport in Virginia - just outside the American capital - and begin checking in for American Airlines Flight 77, boarding about 30 minutes later.

7.25am

Fourth hijack team board flight

The fourth team board Flight 175 at Boston's Logan airport.

7.35am

Ringleader boards flight

Atta and his hijacking team board American Airlines Flight 11 at Logan.

7.59am

Flight 11 departs

Flight 11 hijack team leader Mohamed Atta

Flight 11 hijack team leader Mohamed Atta

Flight 11 - a Boeing 767 with 81 passengers and 11 crew on board - departs 14 minutes late from Logan, bound for Los Angeles. On board are Atta and fellow hijackers Abdulaziz al Omari, Waleed al Shehri, Wail al Shehri, and Satam al Suqami.

8.14am

Flight 175 departs

Leader of the Flight 175 hijack team Marwan al Shehhi

Leader of the Flight 175 hijack team Marwan al Shehhi

Flight 175 - a Boeing 767 with 56 passengers and nine crew on board - takes off 14 minutes late from Logan, also bound for LA. Among the passengers are the hijack team leader Marwan al Shehhi, originally from the United Arab Emirates, and his team members Fayez Banihammad, Hamza al Ghamdi, Ahmed al Ghamdi and Mohand al Shehri.

8.14am

First hijack begins

While two of the hijack teams are still on the ground, Waleed and Wail al Shehri - on Flight 11 - rise from their seats and stab two cabin crew members.

Atta then approaches the cockpit and another hijacker stabs a passenger who tries to stop him. Mace is sprayed in the first and business class cabins.

Five minutes later, another crew member alerts the ground to the stabbings - and shortly after, the plane's transponder is turned off. Air traffic control realise a hijacking has taken place.

8.20am

Flight 77 departs

Hani Hanjour (C) was the hijack leader of Flight 77, acting alongside Salem al Hamzi (L), Nawaf al Hamzi (R) and two others

Hani Hanjour (C) was the hijack leader of Flight 77, acting alongside Salem al Hamzi (L), Nawaf al Hamzi (R) and two others

Flight 77, a Boeing 757 with 58 passengers and six crew on board, departs 10 minutes late from Washington Dulles Airport, bound for LA.

Among the passengers are hijack team leader Hani Hanjour, a 29-year-old from Saudi Arabia, and co-conspirators Nawaf al Hazmi, Khalid al Mihdhar, Majed Moqed and Salem al Hazmi.

8.26am

Flight 11 veers towards New York

Flight 11 makes a sharp turn towards the south, in the direction of New York City. Atta is heard over the radio saying the plane is returning to the airport. Boston air traffic controllers alert other flight controllers about the hijacking.

8.37am

Flight 11 begins a rapid descent.

8.42am

Flight 93 departs

Ziad Jarrah (C) was the leader of the team that hijacked Flight 93, which also included Ahmed al Nami (L) and Ahmed al Haznawi (R)

Ziad Jarrah (C) was the leader of the team that hijacked Flight 93, which also included Ahmed al Nami (L) and Ahmed al Haznawi (R)

Flight 93 - a Boeing 757 with 37 passengers and seven crew on board - departs 42 minutes late from Newark, bound for San Francisco.

Among those on the plane are hijack team leader Ziad Jarrah, a 26-year-old from Lebanon, together with team members Ahmed al Nami, Ahmed al Haznawi and Saeed al Ghamdi.

A fifth potential team member had been refused entry into the US earlier in August by immigration officials.

8.42am

Hijack of Flight 175 begins

On Flight 175, it is thought that the hijackers force their way into the cockpit and stab the pilots to death.

Another tells passengers to get to the back of the cabin, also stabbing flight crew. Al Shehhi then takes over the controls. Five minutes later, it changes course and its transponder's signal is altered.

8.46am

North Tower (WTC1) hit

The hole left in the North Tower after it was hit by Flight 11

The hole left in the North Tower after it was hit by Flight 11

Flight 11 crashes into the north side of the World Trade Center's North Tower - WTC1.

A fireball engulfs floors 93 to 99 of the building, which is 417m (1,368ft) high.

One estimate put the number in the World Trade Center complex at the time at between 16,400 and 18,800.

More than 1,300 are on the floors hit by the plane or above, with some dying instantly.

Some people decide to begin leaving the South Tower immediately, but the order to evacuate is not given.

8.51am

Flight 77 hijacked

On Flight 77, hijackers seize control. It is thought, unlike in the other planes, no crew are attacked and the pilots and flight attendants are herded to the back of the plane with the rest of the passengers. Three minutes later, the plane begins to alter its course towards Washington DC.

8.52am

Fire crews on scene at WTC

Fire crews were on scene in minutes to help the injured reach safety

Fire crews were on scene in minutes to help the injured reach safety

One of the first fire crews at the scene enters the lobby of the North Tower and finds badly burned civilians who had been hit by the fireball.

It is thought jet fuel spilled out from the initial impact site and ignited, affecting a much wider area.

Windows in the street-level lobby were blown out and a lift shaft was destroyed - possibly by jet fuel that had poured down it and exploded.

Fire chiefs quickly determine it will be a rescue, not a firefighting operation. Teams of firefighters begin to head up the stairwells to help those trapped or injured.

8.58am

Helicopters in the air

A police helicopter pilot quickly evaluated that it would impossible to conduct rooftop rescues

A police helicopter pilot quickly evaluated that it would impossible to conduct rooftop rescues

A pilot in one of two police helicopters scrambled to assess the situation reports that it is too dangerous for the New York Police Department's Emergency Service Unit to attempt to pluck people to safety from the roof because it is "too engulfed in flames and heavy smoke".

By this point, NYPD officers are already in the building and are soon joined by more, with the aim of helping people evacuate.

9.03am

Emergency services arrive en masse

Huge numbers of police joined their fire crew colleagues and began to evacuate people from the area

Huge numbers of police joined their fire crew colleagues and began to evacuate people from the area

More than 1,000 first responder emergency personnel are on the scene, in what has already become the largest rescue operation in the history of New York City and New Jersey.

Unfortunately, many of the fire personnel are unable to communicate with other units and the response becomes increasingly confused.

9.03am

South Tower hit

The moment just before Flight 175 struck the South Tower

The moment just before Flight 175 struck the South Tower

Flight 175 crashes into the south side of the South Tower - WTC2 - which is 415m high.

Floors 77 to 85 are engulfed in flames.

Parts of the plane - including an engine, landing gear and a section of fuselage - are jettisoned in various directions.

They hit other buildings - including WTC5, one of the smaller buildings in the complex.

The ultimate number of those killed in the South Tower would be lower than that in the North Tower as some people had decided to evacuate.

Excluding those on the ground and emergency service workers, more than 600 lives were still lost.

9.03am

Bush reads children a story

Andrew Card tells the president about the planes crashing into the World Trade Center during his visit to the Emma E. Booker Elementary School in Sarasota, Florida

Andrew Card tells the president about the planes crashing into the World Trade Center during his visit to the Emma E. Booker Elementary School in Sarasota, Florida

At close to the exact moment the second impact takes place, US President George W Bush enters a classroom of children for his school visit.

Two minutes later, as he prepares to read the children a story, his chief of staff tells him a plane has hit the South Tower and "America is under attack".

He goes ahead with the story - and says later that he did not want to alarm the youngsters.

9.10am

Civilians in towers told to stay put

Emergency call handlers advised people to stay put and wait to be evacuated

Emergency call handlers advised people to stay put and wait to be evacuated

A number of Port Authority employees on the 64th floor contact their organisation's police desk in Jersey City and are told they should "be careful, stay near the stairwells and wait for the police to come up".

Numerous others inside the building are given the same message by emergency call handlers - stay put and wait to be told to evacuate. Many are believed to have later died.

9.14am

Bush and officials moved

Bush speaks to children, staff and the media at Booker Elementary School

Bush speaks to children, staff and the media at Booker Elementary School

Bush is moved to a neighbouring classroom by the US Secret Service, where he and senior officials monitor what is taking place.

He later gives a televised speech at the school to youngsters and teachers at which he says two planes had crashed into the WTC "in an apparent terrorist attack on our country".

9.28am

Flight 93 hijack begins

On Flight 93, hijackers attempt to take over the aircraft.

But with only three "muscle men" as the FBI later dubbed them, and with the pilots knowing the World Trade Center had been hit, it is not as easy for them to do so.

In the following minutes, air traffic controllers hear the sounds of a struggle, moans from one of the pilots and a flight attendant being silenced.

One passenger calls his wife telling her the plane has been hijacked, and that another passenger has died after a stabbing.

After she tells him about the WTC attacks, he says he has heard the hijackers speak about crashing his plane.

Seven minutes later, the plane is turned round and heads towards Washington DC.

9.30am

Faller kills firefighter on ground

First responders had to be increasingly careful getting into the building because of falling debris and people

First responders had to be increasingly careful getting into the building because of falling debris and people

The first firefighter to die on the day is killed when he is hit by a person who has jumped or fallen from the upper storeys of the South Tower, landing at the corner of West and Liberty streets.

The risk of being hit by people or debris falling from above forces fire crews to seek alternative routes of entry into the building.

The Fire Department of New York (FDNY) goes on to lose 343 personnel on the day.

9.37am

Cheney moved to bunker

With President Bush in the air and often out of contact, Dick Cheney ran operations from the White House bunker

With President Bush in the air and often out of contact, Dick Cheney ran operations from the White House bunker

Vice President Dick Cheney heads to the bunker underneath the White House, from where he directs operations as Mr Bush is ferried to Air Force One.

9.37am

Pentagon hit by Flight 77

Scores of people died inside the Pentagon after it was hit by Flight 77

Scores of people died inside the Pentagon after it was hit by Flight 77

Flight 77 crashes into the west side of the Pentagon - eight minutes after engaging manual control.

With no operating transponder and limited radar coverage, controllers were unable to track its movements and unsure where it was before the impact.

As it descended, it made manoeuvres that were described as dangerous for a plane of its type, until it eventually clipped street lamps before hitting the first floor of the Department of Defense's headquarters.

As well as those on the plane, 125 in the Pentagon are killed. Among the plane's passengers is TV news personality Barbara Olson, the wife of US Solicitor General Theodore Olson.

She managed to call her husband to tell him the plane had been hijacked.

9.41am

Falling Man photo taken

The photo that was later named The Falling Man is taken by an Associated Press photographer after a victim trapped on the upper floors of the North Tower - above the impact zone - either jumps or falls. It is estimated between 100 and 200 jumped or fell from the Twin Towers.

9.43am

First claim of responsibility

The first claim of responsibility is made by the Democratic Front for the Liberation of Palestine, but this is later denied by a senior official from the group.

9.45am

US airspace shut down

Airports across the US were closed and planes told to land at the nearest airport

Airports across the US were closed and planes told to land at the nearest airport

US airspace is shut down and all civilian aircraft are ordered to land at the nearest airport.

9.57am

Flight 93 passengers fight back

Passengers on Flight 93 - aware of the WTC attacks after several manage to reach their family by phone - start to take matters into their own hands.

After holding a vote about a revolt, they attempt to seize back control.

For the next few minutes, the voice cockpit recorder picks up the sounds of an intense struggle, with the hijacking pilot threatening to down the plane.

It remains unclear whether the cockpit was breached by the passengers, but they are later described as heroes.

9.58am

South Tower collapses

The aftermath of the South Tower collapse

The aftermath of the South Tower collapse

The South Tower of the World Trade Center collapses - 56 minutes after it was hit by Flight 175.

All civilians and emergency personnel inside are killed, as well a number of individuals - both first responders and civilians - in the concourse, in the Marriott Hotel, and on neighbouring streets.

Huge clouds of dust and pulverised concrete ballooned through the streets of lower Manhattan in the seconds after the South Tower collapsed

Huge clouds of dust and pulverised concrete ballooned through the streets of lower Manhattan in the seconds after the South Tower collapsed

It spreads dust and debris throughout the surrounding streets and leaves a pall of smoke over southern Manhattan.

The National Institute of Standards and Technology later determined the collapse was not due to substandard design, as the severity of the attacks was beyond anything predictable, but that was later criticised by a number of engineers and experts.

The dust left many choking and struggling to breathe

The dust left many choking and struggling to breathe

10am

Order to evacuate

The complete evacuation of the North Tower is ordered. Due to failures in communication equipment, not all fire personnel in attendance receive the order.

10.02-10.13am

Panic spreads to other cities

The 1,450ft Sears Tower in Chicago was one of those evacuated as a precaution

The 1,450ft Sears Tower in Chicago was one of those evacuated as a precaution

With panic spreading and rumours another hijacked plane is in the sky, the Sears Tower in Chicago, the United Nations building in New York City and other tall buildings are evacuated.

10.03am

Flight 93 crashes

The site of the crash in Pennsylvania

The site of the crash in Pennsylvania

Flight 93 crashes into open ground near Shanksville, Pennsylvania at more than 500mph and at an angle of about 40 degrees. Witnesses say it was either upside down or on its side.

10.28am

North Tower collapses

A moment after the collapse of the North Tower, as more dust and smoke spread across the streets of New York City

A moment after the collapse of the North Tower, as more dust and smoke spread across the streets of New York City

The North Tower of the World Trade Center collapses - one hour and 42 minutes after it was hit by Flight 11.

In the process, the Marriott Hotel located in 3 World Trade Center (WTC3) is also largely destroyed.

The Statue of Liberty in New York Harbour after the collapse of the Twin Towers

The Statue of Liberty in New York Harbour after the collapse of the Twin Towers

As it collapses, all civilians alive on the upper floors, an undetermined number below and scores of first responders are killed, including the FDNY Chief of Department, the Port Authority Police Department Superintendent, and many of their senior staff. The total number killed on 11 September would be 2,973.

10.43am

Evacuation of Lower Manhattan

People flee from Manhattan over New York's Brooklyn Bridge

People flee from Manhattan over New York's Brooklyn Bridge

New York Mayor Rudy Giuliani orders an evacuation of Lower Manhattan.

In the minutes and hours afterwards, a human stream is seen heading out of the area, along all northbound streets and avenues and across the bridges connecting the island to the rest of the city.

10.53am

DEFCON3

US Secretary of Defence Donald Rumsfeld raised the threat level to DEFCON3

US Secretary of Defence Donald Rumsfeld raised the threat level to DEFCON3

Defence secretary Donald Rumsfeld puts US on DEFCON3 for the first time since 1973. DEFCON1 is nuclear war.

11am

Canada grounds planes

Canada bans all aircraft - except those operated by the police, military or humanitarian agencies - from taking off from its airports. Canadian airports are also used to allow US planes to land.

12.01pm

Miraculous survival in stairwell

Fourteen people who had been in a section of stairwell in the North Tower climb out alive after miraculously surviving because the spot where they ended up remained standing - protecting them from the building collapsing around them.

Twelve of them were firefighters.

12.15pm

No planes in the air

All planes across the US were grounded

All planes across the US were grounded

All commercial aircraft in mainland US airspace are on the ground and most airports are closed.

3.15pm

Tenet says al Qaeda the likely suspect

Bush moved around the country on Air Force One visiting Barksdale Air Force Base, before heading to Offutt

Bush moved around the country on Air Force One visiting Barksdale Air Force Base, before heading to Offutt

After arriving at Offutt Air Base in Omaha, Mr Bush meets with his principal advisers through a video conference and tells attendees: "We're at war."

Director of Central Intelligence George Tenet says the agency is still assessing who was responsible, but early signs all point to al Qaeda.

5.20pm

WTC7 collapses

7 World Trade Center - WTC7 - a 47-storey building that is part of the complex, collapses, having been on fire since it was hit by debris during the collapse of the North Tower.

The aftermath

14 September 2001

Congress authorises military action

Congress passes legislation authorising "Use of Military Force Against Terrorists", which is signed on 18 September by Mr Bush.

15/16 September 2001

Bush declares war on terror

Mr Bush convenes a war council at Camp David with senior officials to discuss the options for striking back at al Qaeda - including an invasion of Afghanistan - should the Taliban refuse to hand over Osama bin Laden and close terror training camps.

By the end of the weekend, Mr Bush uses the phrase "war on terrorism" for the first time.

Late September 2001

Spies deployed

The US and UK deploy CIA and MI6 operatives into Afghanistan with the aim of bringing on board Afghan warlords disaffected with the Taliban.

7 October 2001

Airstrikes on Afghanistan

Bombing of targets inside Afghanistan begins the US-led invasion of the country. The UK is reported to be heavily involved. Most of the Taliban's forces are beaten within the space of about two months but bin Laden escapes.

20 October 2001

Bin Laden nearly admits involvement

In an inflammatory video circulating among supporters of al Qaeda, Bin Laden refers to attacks on US buildings, saying: "It is what we instigated for a while, in self-defence... So if avenging the killing of our people is terrorism, let history be a witness that we are terrorists... Bush and Blair... don't understand any language but the language of force. Every time they kill us, we kill them."

17 April 2002

Bush calls for Afghan reconstruction

Mr Bush evokes the spirit of the post-World War Two Marshall Plan when he calls for the reconstruction of Afghanistan in a speech at the Virginia Military Institute.

Soon after, the US and its allies are distracted by plans for another war in Iraq.

July 2004

Commission praises heroism

The 9/11 Commission report is published, and makes a series of recommendations, but says that: "As a result of... first responders... the vast majority of civilians below the impact zone were able to evacuate the towers."

It finds that, out of those who died, only 110 - or 5.36% - worked below the impact zones.

October 2004

Bin Laden finally admits involvement

Osama bin Laden, in an audio recording played on the Al Jazeera TV news network, directly says he was behind the 9/11 attacks.

2 May 2011

Bin Laden killed

US Navy SEALs raid bin Laden's compound in the Pakistani city of Abbottabad and kill him and about four others. Afterwards, his body is buried at sea.

Credits:

Words and digital production: Philip Whiteside, international news reporter

Graphics: Pippa Oakley, designer

Sub-editor: Connor Sephton

Pictures: Associated Press; Reuters