Amateur footage appears to show passengers trapped on board a crashed rollercoaster ride at Alton Towers amusement park. People can be heard screaming for help after their carriage collided with another on the ride. The two carriages can be seen locked together rocking back and forth at reduced speed. Four people were seriously injured in the crash
Warning: this video contains strong language and distressing images
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The Alton Towers rollercoaster crash that left four teenagers seriously injured this afternoon is one in a rare history of UK theme park disasters.
Two men and two women were badly hurt at the Staffordshire park when two carriages on the The Smiler attraction collided mid-ride at about 2pm.
Sixteen passengers were on board when their carriage struck another empty car thought to be doing a test run.
Accidents at modern theme parks are rare, but there have been past injuries and even fatalities on Britain's amusement rides.
The UK's worst rollercoaster disaster came in London's Battersea Park in 1972.
