The group of 28 people were left stranded after virtual reality ride Galactica ground to a halt at the top of the first loop at around 2pm, witnesses said. A member of staff had to climb up to comfort them and calm them down after the rollercoaster, which opened in March, broke down during a heavy rain shower.
Staff eventually managed to re-start the rollercoaster and bring the riders back down to the ground.
"We were standing underneath it when the ride stopped and all the passengers were screaming and crying, they sounded terrified," said Kate Smythe, who was there with her family. "We were told the ride had flooded and I wonder if the electrics shorted in the rain."
An Alton Towers spokeswoman said: “On the afternoon of 2nd May, heavy rain obscured a sensor on Galactica which meant that the ride was automatically stopped. This is a standard safety feature on this ride and the ride was working exactly as it is designed to do. The health and safety of our guests is our number one priority and our team followed standard procedures to get the guests off as quickly and as safely as possible. The ride has re-opened.”