Police were called to help evacuate 150 holidaymakers from a “dangerously” overcrowded train during the Easter break.
Passengers reported being packed into carriages “like sardines” aboard the Great Western Railway (GWR) service from London Paddington to Penzance on Good Friday.
Several hours into the journey many were told they would have to leave the train early amid safety fears over the sheer volume of people making the trip.
The problem grew when the heaving train arrived in Plymouth Devon, whereupon even more passengers attempted to board the train – as those standing by the doors were told to get off.
As people spilled out of the carriages onto the platform, they were told to wait for extra carriages to be added to the next train.
Meanwhile the British Transport Police were called when some passengers refused to budge.
But on Monday a spokesman for GWR said the action was necessary and added the operator was working hard to ensure there was no repeat of the chaos during the return journeys.
He said the 10:00am service was "very busy" when it left London Paddington and it "picked up more passengers" as it travelled towards Penzance.
He said: "Two services arrived at Plymouth ahead of the London Paddington service and terminated there, which resulted in a lot of people waiting to board this train.
"The train manager said the situation was unsafe and asked people standing right by the doors to leave."
He said police assisted staff as some passengers did not want to leave.
GWR said a further six carriages were added to a two carriage train that departed about one hour later and took the remaining passengers into Cornwall.
The company also provided another train to Penzance later on Good Friday, admitting the service had been busier than usual.
It said it was looking at ways to prevent a similar situation from occurring in future.
Some passengers who were caught up in the chaos described the situation as "dangerous".
Robert Wyndham, 43, of London, said: "We had booked our ticket weeks ago. But they seemed to be surprised at how many people wanted to go to Cornwall for the Easter bank holiday.
"We were packed in like sardines. It was dangerous and I guess they did what was necessary but it should never have got to that stage."
Eve Conway, who tweeted pictures of the overcrowded carriages, wrote: "Chaotic scene on overcrowded train to Penzance. Passengers lie in aisles, etc. Safety hazard."
Former Director of the BBC World Service Nigel Chapman described the service as "the train from hell" and tweeted that pregnant women were having to "fight to get to the loo." He criticised GWR for having "no accountability or management", train staff as being "stroppy" and the service as being "dangerous and unsafe."
Another passenger Ali Swindell wrote on Facebook: "It was actually dangerous. If anyone had a medical emergency there's no way they could have been seen to. You couldn't even lift your arms properly or turn.
"I asked GWR what the limit was for passengers and they said they didn't have a limit.
"This seems crazy to me. In light of what's been happening recently you would have thought they wouldn't fill trains up to the brim."
Another passenger Chrissie Parker wrote: "It's like this every Bank Holiday.
"I had to stand in the toilet on one journey even though I had a seat booked - someone was in it and refused to move.
"They put on enough carriages, but the amount of people travelling is in excess of what the trains /platforms can handle.
"I do think they should do something about it. It's an accident waiting to happen."
Jennifer Brown wrote: "I was on that train. It was unbelievable overcrowding.
"Passengers were saying that the train was fully reserved a month ago, every seat sold."
A spokesman for the British Transport Police said: "We were contacted on Friday, 25 March, by GWR for assistance with a particularly busy service, arriving into Plymouth at 1.11pm.
"Officers helped rail staff direct passengers from the carriages and onto the platform so they could catch another train and continue their journeys."