It was a windy day–one during which The Smiler and other rides like it should not have been allowed to operate. The same day, at least one other ride in the park was closed due to dangerous wind conditions.

However, The Smiler continued to operate as usual. During the afternoon, The Smiler had been operating with four cars, and staff was preparing to add a fifth to cut down on the ride’s estimated wait time. At this point, ride staff noticed a warning light indicating an issue with the ride’s operation and closed the ride temporarily to call for ride maintenance. While maintenance was busy dealing with the warning light, the rest of the ride staff added the fifth car to the track. 

The engineers finished dealing with the warning light and allowed the ride to reopen. They sent around an empty car to test the track before allowing riders to board. Perhaps due to the high wind speeds, the empty car was unable to complete the circuit. The car stalled on a segment of track, but this went unnoticed by operators who believed there were still only four cars on the track at the time. Four cars were accounted for, and the ride was reopened. 

The first car to be sent through after the reopening was full of passengers. Many modern coasters are equipped with an automatic safety feature that prevents the train from proceeding to the next section of track if the next segment is already occupied by another car. Thus, the rider-filled car stopped before entering the zone with the stalled test car, and ride operators were notified that the next segment still contained a ride vehicle. 

One of the engineers that remained saw the warning and, believing that all operating cars had been accounted for and the warning was a glitch of some sort, manually overrode the safety feature and allowed the full train to proceed into the occupied zone. The occupied train gained speed as it descended the hill and prepared to enter the cobra roll. The full train collided with the rear of the stalled car, leaving the riders with critical injuries. Emergency services were called, but due to the location of the crash being so elevated from the ground, it took nearly five hours to rescue the injured riders.

Thankfully, there were no fatalities in this devastating event, but at least two riders had to undergo leg amputations in the aftermath. Alton Towers cooperated fully in the investigation that followed, and it was determined that the accident itself was due to human error. After the accident, staff was retrained and the ride underwent several safety refurbishments to prevent something like this from ever taking place again.

Safety features such as the automatic stopping mechanism that initially prevented the full train from moving into the occupied zone should have never been overridden without a double and triple check that the zone in question was empty. Additionally, the ride itself should not have been operating that day due to the unsafe wind conditions that caused the test car to stall.

This incident, as tragic and horrifying as it was, could have been much worse. Everyone involved is lucky that there were no casualties as a result of this accident. The Smiler continues to operate in Alton Towers to this day, and since this incident in 2015, the ride has maintained an excellent safety track record.