Rider reports noise like 'a metallic clank' on The Smiler three hours before crash

A person who rode on the Alton Towers roller coaster three hours before it crashed yesterday, seriously injuring four people, told ITV News they heard a sound like "a kind of metallic clank" as they entered the ride's first loop.

The rider, who wishes to remain anonymous, admitted that the sound had scared them, but that they hadn't wanted to alarm their daughters, so they "just had to ride in panic".

Once the ride, a 14-loop coaster called The Smiler, finished the person says they alerted staff.

"I told one of the women who strap you in," they told ITV News. "And I told her that I'd heard something come loose that sounded like a screw or something... She said 'okay, I'll pass the information on'."

Describing the moment that they first heard the sound, the person said: "The very first loop is indoors. We went upside down on that loop and heard something come loose."

Just under three hours later, The Smiler crashed with 16 people riding it.

"It may have absolutely no bearing whatsoever," admits the source.

Two men, aged 27 and 18, and two women, aged 19 and 17, suffered serious leg injuries when two carriages on the Smiler ride crashed.

Asked for comment on the claims Alton Towers told ITV News "At present we are working closely with the health and safety executive to investigate the incident. We cannot comment further on individual speculation."