As the American Airlines flight they were on board flew over New York on the morning of September 11, 2001, Jeffrey Sandell's fellow passengers suddenly became aware of the smoke billowing from the north tower of the World Trade Center.

The retired Norfolk builder and his wife Ann – who died in 2002 – were about to arrive in the city for what was to be the most exciting part of their tour of America that summer.

At that stage, they were unaware that the events they were witnessing from their aircraft were world-changing. But as they landed, it rapidly became apparent that America was in turmoil.

Mr Sandell, 75, from Norwich Road, Wroxham, recalled: 'Our plane was less than half full with about 50 people on board and most of them seemed like business people.

'One man suddenly said 'the World Trade Center is on fire', so we moved over to a window seat to have a look. We saw that the number one tower was smoking badly from the top. We did not know how serious it was but it looked like a serious fire.

'Then I noticed a plane flying below us. It was flying between us and the towers. The plane then banked sharply round and the next thing I saw was a terrific explosion on the number two tower about halfway down.'

Their aircraft, which had taken off from Nashville earlier that morning, continued and landed safely at New York's La Guardia airport soon after.

He said the pilot had remained calm, even though he was undoubtedly aware of what was going on.

Still unaware of the full scale of the attack, the couple were driven into New York.

'We wanted to see the shows on Broadway and the next day we were planning to go to the top of the World Trade Center for the view and see the Statue of Liberty,' said Mr Sandell. But with the ensuing chaos and fear as people fled Manhattan, they were unable to reach their hotel and were advised to take the train to a suburb where there was said to be accommodation.It was on that journey that they began talking to New Yorkers heading out of the city and one of the passengers – Judy Fox – promised the couple a bed for the night.

It was only as they settled and began to build up a clearer picture of the events of the day that they realised just how close they had come to the attack.

'I still don't think we realised the seriousness of the incident until we saw it on television,' said Mr Sandell. 'We saw a plane that was flying low and wondered why it was so low, but we did not realise until later the severity or the scale of it.'

Mr Sandell has remained in contact with the family that helped them but he never did see New York's attractions and, following Mrs Sandell's death after a fight with cancer, Mr Sandell has not travelled overseas since.