More than 2,000 people were stranded beneath the English Channel for up to 16 hours when their Eurostar trains came to a halt in a tunnel, leaving many of them without food, water _ or any idea of what was happening.
In the end, they all emerged safe on Friday night, but some suffered claustrophobia or panic attacks, and many passengers complained that Eurostar staff members had done little to help them through the ordeal, which forced some to walk part of the dark tunnel, 24 miles (38 kilometers) of which is under water.
Eurostar's executives have offered apologies, refunds, free travel and more, but the company has canceled all passenger services through the Channel Tunnel until Monday in a bid to figure out what happened.
"It was just pandemonium," said Lee Godfrey, who was returning to London from Disneyland Paris with his family when it was caught in the tunnel. He said people suffered asthma attacks and fainted after the train's power went out, cutting off light and air vents.
"People were very, very panicky," he told BBC radio, complaining of poor communication and saying that some passengers had to open the emergency doors themselves.
Godfrey's was one of four trains that were stuck in the tunnel Friday evening for reasons that remain unclear.
Eurostar officials have speculated that the quick transition from the icy cold of France, which is suffering some of its worst winter weather in years, to the relative warmth of the tunnel could have interfered with the trains' electrical systems. But the company's chief operating officer, Nicolas Petrovic, said Eurostar will have to investigate why the trains broke down.
"We've never seen anything like that at Eurostar," Petrovic told France-Info radio on Saturday.
The company has canceled regularly scheduled services until Monday for test runs.
"We don't want a repeat of last night," Eurostar spokesman Paul Gorman said.
Some passengers were evacuated by being taken through the darkened train tunnel onto shuttles. Others were left aboard two trains that were linked together and pushed to London by smaller diesel trains.
Parisian Gregoire Sentilhes described confusion as authorities struggled to evacuate passengers.
"We spent the night inside the tunnel," he said. "At 6 a.m. we were taken out of the train by firefighters. We walked for around a mile (1.6 kilometers) with our luggage. We went into another Eurostar train and we were trapped on it, going back and forth inside the tunnel."
He said passengers were suffering panic attacks, lacked anything to drink and didn't know what was happening. Some also complained about chaotic and poorly-organized efforts to get them home.
That confusion extended into Saturday evening.
Early Saturday Eurostar announced it was sending stranded passengers home from London in three special trains _ only to cancel the service a few hours later. Two trains dispatched from Paris also canceled _ one broke down shortly after leaving the tunnel, while another was stopped at Lille in northern France.
Chief Executive Richard Brown said the company was "very, very sorry that so many passengers were inconvenienced last night and this morning due to weather conditions in northern France. We are working hard to get passengers home. We will give them full refunds and another ticket."
Eurostar provides train service linking London to Paris and Brussels. It is usually thronged with holiday travelers this time of year.
The train service's reputation for safe operation suffered a setback in September, 2008, after a fire broke out as one of the trains entered the 50 kilometer (30 mile) tunnel. Service was cut back for five months as extensive damage was repaired.
On Saturday, travel for motorists hoping to cross the English Channel on ferries and via the Channel Tunnel was also badly disrupted. Police in Kent, England, warned drivers not to travel to the port of Dover except in emergencies because of massive traffic snarls caused by problems in the tunnel and in the French port of Calais.
Police put in motion a contingency plan to allow up to 2,300 trucks hoping to cross the English Channel to park on highways until the situation improves. Red Cross workers provided hot drinks and water to motorists trapped in their cars for up to 12 hours.
Associated Press Writer Cecile Brisson in Paris contributed to this report.