Alton Towers has been closed while an investigation continues into a rollercoaster accident that left four people with serious injuries.

Two carriages crashed on the Smiler ride at the Staffordshire theme park on Tuesday, leaving some passengers trapped for over four hours.

Two men, aged 27 and 18, a woman aged 19 and a girl, 17, suffered serious leg injuries in the crash.

Nick Varney, chief executive of the park's owners Merlin Entertainments, said he was "totally devastated" by what happened.