"Therefore we e-stopped the ride as soon as possible and evacuated all guests."
Others at the park took to Twitter to post pictures. Images showed about five people making their way down the tracks carefully.
Daniel Pashley posted a series of photographs and wrote: "People evacuated from stuck roller coaster at Thorpe Park. Everyone safe, says employee."
He added later: "Roller coaster stuck at Thorpe Park - guests being walked down to safety. Employee says nobody hurt."
The ride was opened again later in the afternoon. The park's spokesman confirmed no one had been injured.