The "21 hours of chaos and trauma" for the 14 boys and girls from Healesville High School and their minders began in the Indian city of Haridwar on December 8 when they boarded an overnight train to Udaipur. According to statements seen by The Age, Indian rail officials were unhelpful in trying to change the pre-organised seat allocations and the efforts by teachers to negotiate swaps with other passengers were met with open hostility. Teachers and the World Challenge team leader managed to group students in clusters, but there were more arguments when new passengers boarded the train and demanded their sleeper beds from the teens. Some time into the journey, Ms O'Connor's 16-year-old daughter went to the toilet with a friend who didn't feel safe going alone. The teenager, who has requested not to be named, said she was groped on the backside by a male passenger.

After getting over her shock, the student, who had taken a job and saved for 18 months to pay for the $7500 World Challenge experience, pointed out the man to teachers. "I said, 'That's him right there.' A teacher and [the World Challenge team leader] walked up and stopped him and basically went off," she told The Age. "I felt confident to do my own thing. I went up and said, 'You've been staring at us. Don't touch me and don't touch the girls.' He didn't know any English and he just stood there silently. My legs were shaking; it was affecting me physically a little bit. "Just before we got off the train, my friend just burst into tears, saying, 'I can't believe that happened, I'm crying for everyone'. Girls were trying to sleep and men and women were grabbing them and shaking them trying to get them to move. It was such an intense thing to go through." In an email to the family, seen by The Age, Healesville High School principal Allan Rennick said World Challenge "made a huge mess" of the experience and had "lost the confidence of all involved".

An Education Department spokeswoman said the incident had been referred to Indian police and that it would conduct its own review into how it was handled by World Challenge. World Challenge has been operating for more 30 years and has more than 150,000 alumni Credit:Instagram/World Challenge World Challenge, which has been operating for more than 30 years and has some 150,000 alumni, describes its programs as complementing school learning and providing "students the opportunity to become true life-learners and true global citizens". General manager Mark Walters said the booking error was made by its on-the-ground agency in India and processes would be changed to ensure students were always grouped together for future train journeys. He said hundreds of students were sent to India each year and the Udaipur train incident was an isolated one.

"We had a great ratio of staff there ... better than one to five. Unfortunately, there's a local man who has done something horrible," he said. Ms O'Connor criticised World Challenge for not informing parents immediately after the train journey. Her daughter said the group was asked not to call their parents in the days following the assault so World Challenge could be "briefed and debriefed" - an assertion Mr Walters said was "unlikely". Ms O'Connor said World Challenge management waited a week before making its first direct contact with her.

An email was sent to the Healesville principal several days after the train journey, which Ms O'Connor also slammed for using the words "touched inappropriately" to describe what happened to her daughter. "This is sexual assault. They're not acknowledging the severity," Ms O'Connor said. Mr Walters said the words were chosen to provide the "right context" for worried parents, and were not intended to play down the seriousness of the incident. He said he personally greeted parents and students at the airport and has offered counselling services. The student has declined to make a formal complaint to police.