Here, reporter Siobhan Ryan describes the terror on what should have been a routine journey home on Wednesday's 18.36 to Portsmouth.

As the train pulled out I sat down next to the window in the last carriage.

I would be home by about 7.15pm and be able to relax for the evening. Or so I thought.

I got out my book and settled down to read, little knowing that a short time later I would be involved in a real-life thriller of my own.

Once I start reading a book I become buried in it and ignore everything around me.

I was vaguely aware of the train stopping and starting at several stations and glanced up as the train pulled out of Shoreham.

It began to pick up speed and I had just got to a point in the book where a murderer was about to be revealed when I felt the train start to brake really hard.

I looked up as it kept on braking and the carriage started to shake from side to side.

There was a horrible screeching noise of brakes that seemed to go on and on and it felt as though the train was never going to stop.

I was jolted from side to side in my seat and I could smell burning.

People around me initially looked relatively calm but their expressions changed to ones of horror as they began to realise something was very badly wrong.

It is a bit of a clich to say my life flashed before my eyes, but I really thought I'd had it.

All I could think of were all the other train crashes I had heard about as I was waiting for the sickening crunch and for the carriage to burst into flames or roll on its side.

Fellow passengers started to shout and swear around me as the train finally screeched to a halt and there was a moment of silence before everyone started talking at once.

A few seconds later the guard's voice came over the tannoy, asking people to stay calm, but a couple of moments later the lights went out and the train was plunged into darkness.

All around me people whipped out their mobile phones and called their nearest and dearest to tell them what had happened.

Everyone around me asked each other if they were all right and a guard later came through the carriage asking if anyone was injured.

He said all the power had been cut off so there was no chance of a train crashing into the back of us.

There was nothing we could do except wait and while doing this I spoke to other passengers and kept the newsroom updated.

Once the initial shock was over there was a real sense of relief in the air as people realised no one was badly hurt and it was only a matter of waiting for rescue.

The train stayed in darkness but we soon saw the guard's flashlights going up and down the track as they checked the line and then in what seemed to be a really short space of time we could see the police, fire and ambulance crews arriving.

Finally came the call that the fire brigade had installed ladders leading from the train up the embankment and they were ready to let us out.

By then everyone was just eager to get out.

I'm not a smoker but I could tell people around me were just gasping for a cigarette - I almost felt like lighting up myself.

I finally reached the ladder and made my way out carefully and it was such a relief to feel safe again.

I've ended up with a bit of a stiff knee and a sore back but I'm in one piece and that's all that matters.

I know I'm lucky. It could have been so much worse.