One of the first orders US president George W Bush gave after an airliner slammed into the North Tower of the World Trade Centre on the morning of September 11 was to shut down American air space.

US Air Force fighter jets were scrambled with orders to shoot down commercial aircraft that disobeyed the directive.

It was a difficult decision to take and one that created a logistical nightmare for the Bush administration.

Hundreds of passenger aircraft were still in the air en route to US airports.

But the lockdown meant they were now barred from entry and would have to find alternative landing sites – fast.

Patricia Peets had started her shift at Bermuda’s LF Wade International Airport at 6.30am that morning.

It began like any other – but two hours or so into the day, she got a call from an airport fire officer who had heard of an incident at Manhattan’s World Trade Centre.

First reports suggested that a light aircraft had collided with one of the skyscrapers.

Ms Peets, isolated in her tower, knew nothing of the incident but decided to investigate further.

She contacted a colleague at the New York Air Route Control Centre in Long Island for more information.

It was only then that she discovered that America was under attack by aircraft transformed into missiles.

Ms Peets notified her manager and the team immediately went on high alert.

There was a likelihood that aircraft would have to be diverted to Bermuda and the island’s airport needed to be prepared.

Ms Peets displayed the same coolheadedness she needed 20 years ago as she remembered the events of the day.

She said: “I had to remain calm and alert. Our training prepares us to remain calm in emergencies, but this was an extreme situation.

“I didn’t panic as we are always trained to remain calm. We can de-stress once we leave work, but work is work.”

But Ms Peets admitted: “I was very concerned about my fellow air traffic controllers in New York and the stress that they were going through. They had informed us that this was a terrorist attack.”

There were other potential distractions – Ms Peets’ two sisters worked in Manhattan and she feared for their safety.

Her shift partner that day was an American whose wife was also lived and worked in New York.

But she said personal concerns had to be put to one side.

The airport may have to deal with up to 20 aircraft arrivals a day at its busiest.

But Ms Peets and her colleague guided 15 passenger jets to safety in the space of an hour on 9/11.

She said with cool understatement: “It was pretty intense for a while.

“The flights came relatively close as they were already in New York and Bermuda air space, which was about to be closed.

Ms Peets praised the pilots of aircraft that flew into Bermuda.

She said: “They all remained calm. We knew they were aware and so they were co-operative.”

Ms Peets finally finished her shift at 3pm, travelled home, and watched the television news “in disbelief”.

She was greeted with the unfamiliar sight of Bermuda Regiment soldiers on guard at the control tower when she arrived for work the next morning.

Ms Peets said: “I realised how vulnerable Bermuda is and how laid back we are at times when things are happening around us.”

But – 20 years on – Ms Peets played down her role on the day.

She said: “I was fortunate in that I had good training and worked with some very good people.

“I was always taught that being an air traffic controller wasn’t for the faint-hearted.

“It’s a job that has enormous responsibility – you have people’s lives in your hands.

“But – at the end of the day – I was just doing my job.”