Some 200 passengers were last night freed from a rail tunnel after being trapped when a landslide derailed a London to Cardiff service.
The engine of the high-speed train hit debris from the landslide, including a tree which had fallen on to the track near Bristol, an Avon and Somerset police spokesman said.
The train's eight carriages continued into the short Patchway tunnel, where they were trapped.
Police closed the A38 immediately after the incident, which happened shortly after 6.30 p.m.
No passengers were injured in the incident, an ambulance service spokeswoman said.
One man in his 50s was given oxygen at the scene after he complained of respiratory problems.
"His condition was probably due to the lack of oxygen in the tunnel," the spokeswoman said.
A Railtrack spokesman said the landslip, which was caused by torrential rain, was 200 yards from the entrance of the tunnel and covered one rail.
The pile of earth and vegetation about 2ft thick caused the front wheels of the engine to leave the track at 6.10 p.m., he added.
About 200 people were later escorted up steps on the side of the tunnel to the road where coaches provided by Railtrack were waiting.
The Railtrack spokesman added: "The driver of the train came to a controlled stop inside the tunnel and all the carriages remained upright.
"The passengers would not have felt the train hitting the landslide because it was fairly small. All they would have been aware of was fairly sharp breaking. Everybody will now continue their journey on coaches."
He added that the line would be closed until this morning and trains were being diverted via Gloucester, adding about 45 minutes to the journey time.