Just weeks earlier we'd fallen in love with New York – an incredible place that truly lived up to its nickname as the city that never sleeps.

Now we were returning, just a few days after the most terrible day in its history, and the contrast could not have been starker.

It was night-time as we crossed one of the bridges over the Hudson River to Manhattan Island and we could see the devastation.

There was a cloud of swirling dust and smoking embers, glowing like a fierce orange maelstrom because of the light pollution.

The city we had fallen in love with, wasn't the same city at all.

Like so many tourists before us we took the Staten Island ferry. But the Statue of Liberty seemed to be a sad symbol of a way of life under attack, rather than a proud celebration of freedom.

And the skyline of lower Manhattan seemed terribly out of kilter and almost unbalanced without the World Trade Center towers.

We walked from the ferry terminal up past Ground Zero, staring in disbelief at the dust that covered everything.

A shoe shop's windows were intact, but still its entire stock inside was covered in a layer of dust, and people had used their fingers to daub messages of support and sadness on the dusty glass. 'God Bless America,' they had written.

It was awful to walk past the twisted remains of the towers. As a tourist I felt guilty at being there, but I justified it by telling myself that it was an atrocity that people of all nationalities should never forget.

But most heartbreaking of all were the missing posters that families and friends had plastered all around the downtown area.

Hundreds of pictures of sons, daughters, mothers, fathers, brothers and sisters, underscored by desperate pleas for news on their whereabouts. And it brought home the huge scale of the loss of human life even before the authorities had been able to work out the enormous death toll.

There was also the palpably strange atmosphere that pervaded Times Square.

Whole floors of many restaurants had been given over to feeding rescue workers, and peaceful demonstrators gathered to protest against a kneejerk retaliation. But emotions were running high, and people who had lost loved ones couldn't contain their anger and soon the square was teeming with riot police as the atmosphere teetered on the brink.

The bars were all screening the benefit concert America: A Tribute to Heroes, and Billy Joel's performance of New York State of Mind hit a particularly poignant note.

Little more than a month earlier, my best friend from university and I had flown into New York for a six-week backpacking tour around the Land of the Free.

Joey had just spent a year of her course studying in Miami and making friends from across the country, and the chance to experience real American homes and be shown around by the locals was too good an opportunity to miss.

We were shown around Spanish Harlem by Jumoke, a happy-go-lucky, 6ft 6in basketball player who we called Mo, and marvelled at the area's walls of graffiti, saw Central Park, the Empire State Building and so many other tourist sites.

We couldn't fit it all in, but vowed to do more when we returned in around five weeks. Little did we know then what lay in store for the Big Apple.

Our whirlwind tour by Greyhound took in Boston, Toronto, Chicago, Montana, Vancouver, Seattle, Portland, San Francisco, Las Vegas, the Grand Canyon and Monument Valley, New Orleans. The next stop was Miami, with a trip to Key West, and we bunked down with friends in the university halls of residence. It was here that we saw the terrible events unfold on television.

There were tears and, being British, the only thing we could think to do was to make everyone a cup of tea with the teabags we'd had the foresight to pack.

On campus we bumped into Mo, our New York host.

He had lost a cousin who worked in the Twin Towers and was distraught. People across the country wanted to help in some way, so students queued to donate blood for the injured.

We were stared at as we walked past and were asked to join, but upon hearing our British accents they realised why we wouldn't be allowed.

The university had a day where everyone wore red, white and blue, in a show of solidarity, and at least in this we could take part.

We stayed in Miami for longer than we had planned, because our next two destinations were Washington DC and New York.

When the trip was over I vowed that I would one day return and it's something I still intend to do. I'm sure it will have regained the verve and excitement it had before that devastating day, but I'd like to see it with my own eyes.