Eurotunnel Le Shuttle runs trains that carry passenger and freight vehicles through a tunnel between England and France.
The breakdown affected the 3.50 pm local time service from Calais, France, to Folkestone, England, which was carrying hundreds of people as well as several dogs, the PA Media news agency reported.
Passengers packed into a bus carriage on the Eurotunnel.
Michael Harrison / Twitter / PA Media / PA
Passenger Michael Harrison told PA about the unnerving experience.
“We got on the 3.50 pm crossing, approximately 10 minutes in the lights went out and the train stopped. We were told they needed to investigate an issue with the wheels,” he said.
“It took approximately one and a half hours for them to investigate and obviously not find anything. They reset things and set off for another five minutes,” added Harrison. “It happened again at which time we waited a further couple of hours to decide they couldn’t see a problem but had to evacuate the train to another train.”
Passengers were then evacuated through the emergency link tunnel to the service tunnel, walking for around 10 minutes until they reached another train, Harrison told PA.
Further issues with the replacement train meant passengers finally arrived in the UK six hours after boarding, he added.
The Eurotunnel Le Shuttle service normally takes 35 minutes to make the journey between Folkestone and Calais.
A second passenger told PA that “several people were freaking out about being down in the service tunnel, it’s a bit of a weird place. We were stuck down there for at least five hours.”
Fellow passenger Kate Scott said temperatures in the tunnel were an issue.
“It was hot, there was no air con, they gave out water but we didn’t really know what was going on,” she said.
Sarah Fellows, 37, told PA that “the service tunnel was terrifying.”
“It was like a disaster movie. You were just walking into the abyss not knowing what was happening. We all had to stay under the sea in this big queue,” she said.
“There was a woman crying in the tunnel, another woman having a panic attack who was traveling alone,” added Fellows. “They were expecting really older people to walk for a mile down the middle of a tunnel under the sea.”
“I was panicking at one point and Border Force told us the tunnel had been evacuated one other time in the last 17 years, not recently,” she said.
The issue also had knock-on effects on later services.
CNN has contacted Eurotunnel for further comment on the incident.
The Channel Tunnel revolutionized travel between the UK and mainland Europe when it opened in May 1994, making the journey far faster than the equivalent ferry route.
It had been mooted for more than 180 years before British and French workers broke ground and began digging toward each other in 1988.
It took six years for 13,000 workers to build the 31.4 mile tunnel, 23.5 miles of which run undersea, making it the longest of its kind in the world.