By Brian Wheeler
BBC News reporter, on the Northern Line
Being stuck in a tunnel for 40 minutes is not an unusual occurrence on the London underground.
London is getting back to normal
But on the morning after the worst peacetime bomb attacks Britain has seen, even the most routine-sounding tannoy announcements took on a more sinister aspect.
The thought of the horrific events unfolding less than 24 hours earlier, in carriages exactly like the one we were sitting in, must have been on everyone's mind.
But no one panicked when our train ground to a halt or, as the silent minutes ticked by, looked like they feared for their safety.
I started my journey, as usual, at Kentish Town station.
The platform had been much less crowded than normal and nobody was speaking to each other, but then they never do.
The trains appeared to be running smoothly and, reassuringly, it was still impossible to get a seat.
The Northern Line passes through King's Cross station, which, we were told, was still closed, as a result of Thursday's bomb blast.
There was little solace to be had in the newspapers
As our train ground to a halt just outside Camden Town, a familiar feeling of resigned frustration washed over the carriage. This is par for the course for the underground.
But a few nervous glances were exchanged when the driver informed us that there had been a security alert at Euston.
One young woman looked a bit frightened. Others just buried themselves in their books or stared into space. A few tried to snooze.
There was absolute silence.
Normally, in a situation like this, people try to alleviate the boredom by reading their newspapers.
And today was no different - except the headlines they were reading were hardly a source of light relief.
"There was fire everywhere, everyone was screaming" said one, referring to the tragedy that had happened a few thousand metres from where we were sitting.
The platform was less crowded than normal
The rustling of the newspapers, as we sat there in total silence, only seemed to add to the growing tension. But there were few outward signs that my fellow passengers were worried about their safety.
The driver was doing his best to sound reassuring in his tannoy announcements, sounding not unlike an airline pilot warning passengers about a spot of turbulence.
But some of the messages were not ones I had heard before, in years of commuting by tube.
Twice a recorded woman's voice advised us to hold on tight because the train was about to move forward slowly and then stop suddenly.
At one point, the driver said an official was walking down the track toward the train.
A light flicked on in the tunnel. This did not feel quite right.
Even the electronic ticker that tells you which station is ahead was corrupted.
Eventually we inched slowly into Mornington Crescent, only making it about half way along the platform.
We were "de-trained" and about half of the passengers decided to head for the exit. The rest of us waited for another train.
Rachel Cass: 'Train was empty'
If anyone was feeling anxious, they were not letting it show. Yet talking to commuters earlier at Kentish Town revealed just how worried some people were about using London's transport system in the aftermath of Thursday's attacks.
Louise Macdonald, 22, who works in Kensington, said she did not want to get on a bus when she got up this morning.
"I rang my manager and had a little cry and said I don't want to come in.
"He just said 'so you are not going to catch public transport for the rest of your life?' He is right, of course."
Kerry Miller, 19, who works in a post room, said: "I thought about not coming in, but my family talked me into it. I never normally travel by tube, let alone now this has happened."
Other people were more philosophical.
Abbie Kenyon, 27, who works at the Victoria and Albert museum, said: "I don't think anyone is particularly scared there is going to be another attack.
"Myself and a lot of my friends have feared something like this happening for several years.
"I don't think it is going to cross my mind any more than it normally would."
Ben Billington said: "I just think you have to get on with it. The chances of a bomb actually being present are so small."
Rachel Cass, 21, said she was "terrified" at the prospect of using the tube again, but "you have to get on with it".
"The train was absolutely empty. It is the first time I have had a tube in a rush hour when it has been like that.
"It was the usual tube atmosphere. I thought it would be a bit more friendly."