Sue Arnold: All trains stopped at Watford Junction

As she passed, I tapped her on the arm. 'The trouble is, I live in London,' I said

My Virgin train from Chester on Thursday morning was supposed to get into Euston at 10.27am. At about quarter to ten the couple from Llandudno opposite who had been talking about their special offer package long weekend City Break including two shows in London's glamorous West End (the wife was reading the brochure out loud) had a call on their mobile. It was their son to tell them that they might have to get a taxi at Euston because he'd heard there had been a massive power surge and a lot of the Tubes weren't running.

Did the Tubes often break down in London? she asked me. Yes, I said, all the time, but it's usually signal failure on the District Line or someone throwing themselves on to the track at Embankment.

And then the mobile belonging to the man tapping away on his laptop across the aisle struck up the by now familiar "Overture to William Tell" for the umpteenth time since he'd got on at Crewe. "What sort of incident?" we all heard him say, just as we had all heard him discussing the point of sales promotion for the novelty stationery his company produced and whether the spreadsheets Terry had submitted the previous week were up to scratch.

When he finished the call he closed his laptop deliberately and stood up with the purposeful air of a man who knows exactly what to do in a crisis. A born leader.

We all stopped whatever we were doing - eating all-day breakfast baps from the buffet, thumbing through OK magazine, staring out at the deeply uninteresting countryside around Leyton Buzzard, to listen to what he had to say. By the look on his face it was going to be important.

Alas, we never heard it. The novelty stationer was drowned out by a crackling on the loudspeaker system and the announcement from the guard that owing to a series of major incidents in central London all Virgin trains would be terminating at Watford Junction.

As if on cue everyone's mobile phones started ringing at once - Vivaldi, Mozart, Beethoven's 5th, 9th, "Für Elise" and "Moonlight", "Mission Impossible" and "Crazy Frog" - I've never heard such a cacophony. It reminded me of an avant-garde concert featuring mobile phones and audience participation I was once taken to in Hamburg, where we were seated according to our ringtones. We would be told, the usherette said, when to join in with the orchestra. Before it started, a man came on to the stage and reminded us to make sure that we had our mobiles switched on.

"Major explosions, hundreds killed, fleets of ambulances, suicide bombers, total chaos ..." Snatches of conversations wafted across the seats, and then the automatic doors at the end of coach B opened and the flame-haired Virgin Trains on-board customer relations supervisor came in, chest heaving, and said passionately that she would strongly recommend everyone to stay on the train when we got to Watford Junction and go straight back north with her, where they would be safe. Nothing, she said, was worth the risk trying to get to London.

As she passed, I tapped her on the arm. "The trouble is, I live in London," I said. For some reason the admission made me feel slightly guilty, as if I was confessing to having a secret eating disorder or a criminal record for stealing hotel bath towels. The woman beside me, who had told me she lived in Wandsworth and wondered if she could rent her house during the forthcoming Olympics as lucratively as she did for Wimbledon every year, kept quiet.

"Good luck," said the man from Llandudno when I got off at Watford Junction and headed for London's glamorous West End. No trains, no buses, no Tubes, no taxis, and now there was an additional problem. Due to network surge, no mobile phones. We were like shades in Hades. Doomed to wander purposelessly for eternity in the underworld of Watford Junction station.

I sat on my case, plugged in my earphones and listened to rolling news on my mini radio. A reporter was describing the chaos around her at one of the bombed stations, and the heroism of the lone policeman who had been carrying bodies up from the wreckage to the street. He looked exhausted, she said, and his face was black with grime, his clothes torn, his eyes were streaming.

"Would you say that he had the look of a man who has witnessed the sort of trauma that few people experience in their entire lifetime?" asked the presenter back in the studio. Yes, she said.