Passengers were evacuated to the side of the track after smoke was spotted coming from a train in Cardiff.
The single carriage train was travelling from Cardiff Central to Coryton when it was stopped about half a mile south of the junction at Heath Low Level.
The 32 passengers on the train were all safely taken off the train and emergency services were sent to the scene.
Passenger David Carbis, who was travelling home to Llanishen after visiting a friend in Bridgend, when he got caught up in the drama.
He said: "We had just left Queen Street when the fire alarm went off and then all the power went.
"The conductor came out and was in contact with the driver and then we saw some smoke coming out of the window. It was quite thick. The conductor told us to evacuate the train. I was the first one off and then was able to help some of the others.
"All the passengers were very calm and we had to wait at the side of the track until the rescue train came to get us. There were lot of people from the emergency services who turned up and brilliant.
"It was slightly longer than the 10 minute journey I was expecting, but it was nice to see everyone looking out for each other and good that everyone was safe."
Another train was being sent to collect the passengers and an engineer was sent to the train.
