The Smiler ride at Alton Towers was evacuated this morning.
The rollercoaster was evacuated just after 10am when a visitor triggered an alarm.
A spokesman for Alton Towers said: “At 10.15am today, an assisted exit took place in the station when a guest, at the end of their ride, held their harness down during the routine harness release, triggering our sensors.
“The ride then needed to be reset as required by our operating processes and is now re-open.”
In June 2015, 16 people were injured and two teenage girls needed leg amputations after a 90mph crash on the Smiler ride.
The operator of Alton Towers, Merlin, was fined £5million last September following the incident.