Four planes, 19 hijackers and 2,819 dead: the facts about September 11, 2001 still have the power to shock.

On the morning of September 11, 2001, the world woke up as normal. In New York, 50,000 people made their way to work in the Twin Towers that had been standing proudly over Manhattan since 1970. At 7.59am, 92 passengers and crew took off on American Airlines Flight 11 from Boston, Massachusetts bound for Los Angeles.

At 8.46am Eastern Standard Time (EST), that same plane crashed into the World Trade Center North Tower, killing everyone onboard instantly, as well as an unknown number of people who were sitting at their desks. Three minutes later, images of the gaping hole between the 92rd and 98th floors of the building were beamed across the USA by CNN. People watching, including office workers in the neighbouring tower, gasped at what seemed a terrible accident. Helpless, they watched the infernal aftermath.

The BBC began its coverage at 8.58am EST, so Britain was tuned in when, just after 2pm here, a second plane flew into the South Tower with 65 people on board. It hit lower this time, between the 77th and 85th floors. Only four people on the floors above made it to safety, down the only intact stairwell. It became instantly clear that this was no accident. President George W Bush confirmed this at 9.30am EST, calling it an “apparent attack on our country” in his address to the nation.

Just half an hour later, the South Tower collapsed. It was followed by the North Tower, 29 minutes later. The fires were so intense they burned for 99 days at what would be called Ground Zero; 1,616 death certificates had to be issued without bodies despite a 230-day search. Phone lines jammed as people called friends and family inside the towers. They saw bodies fall from the burning buildings and prayed they wouldn’t recognise a husband or father (male fatalities outnumbered women 3:1). We now know that some on the upper floors jumped, driven out by the extreme heat and suffocating smoke. The descent from top of the building took 12 seconds and those near the scene described the window-shaking impact as they hit the ground. One firefighter was killed by a falling body, and a further 343 firefighters and paramedics died on the scene, alongside 23 NYPD officers.

That morning, terrorists stormed the cockpit of Flight 93 from Newark to San Francisco, taking control of the plane. Realising what lay ahead, passengers called loved ones to say their goodbyes then overwhelmed the hijackers, who crashed the plane in rural Pennsylvania. Forty four died. That Boeing 757 was bound for the Capitol or the White House. A fourth plane was flown into the Pentagon, killing 126 on the ground and all 64 onboard. In total, 2,819 people died during the attacks, or as a direct result of them.

International flights already in the air were redirected away from America, offices shut down, New Yorkers were told to stay indoors. The world had never seen anything like it before, and panicked. People stocked up larders as if for nuclear winter. Until then, airport security had checked for explosives – in fact, several of the hijackers had been flagged up on check-in and their bags thoroughly searched. Air travel instantly changed forever. Never before had passengers been weapons.

Who was responsible? We soon knew: 19 radicalised Muslim Egyptian, Saudi, Emirati and Lebanese suicide bombers, some of whom trained as pilots in the USA. President Bush declared, “Make no mistake, we will hunt down and punish those responsible for these cowardly acts”. Before 9/11, few people had ever heard of Al Qaeda or its founder, Osama Bin Laden. But now hunting them down was the USA’s top priority. The ‘War On Terror’ began 26 days later in Afghanistan, to depose the ruling Taliban and capture Al Qaeda operatives based there.

In the following days, families frantically searched hospitals for their loved ones. Some found them but many bodies were never recovered. Stories of human tragedy and survival emerged. Unbelievably, 16 people survived inside the collapse of the towers. The world praised the heroism of the emergency services, many of whom lost their lives. But there were also people who lied, wanting to be part of the tragedy: Tania Head, who initially symbolised the courage of the survivors and was president and a leading fundraiser of the World Trade Centre Survivors’ Network, was exposed as a fantasist who had been nowhere near the buildings on 9/11.

As time went on, the economy recovered, but 3,051 children were left without a parent; 422,000 people suffered from post-traumatic stress. Things went back to normal, but have never been the same. In the UK, our hearts went out to all Americans, 20% of whom knew someone who was hurt or killed. Our lives changed too: we tightened security measures, scrutinised radical Muslim preachers, hoped terrorists wouldn’t strike here. Four years later, they did.

Picture credits: Rex Features