Policeman's safe cycling demonstration goes very wrong, very fast

You know exactly what's going to happen in the clip below the minute you start watching it.

All the elements are there: the crowd of onlookers, the steep flight of concrete steps, and the policeman in the helmet and the high-vis yellow jacket, who was apparently on hand to demonstrate cycling safety to children. It was only ever going to go one way.

"Police were staging a safe way for kids to go down the stairs on their bikes and the policeman failed miserably," said a man named Derek, who uploaded the clip to Twitter, was quoted as saying in the Daily Record.

"He took it in good spirits. He was fine, just embarrassed."

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At the time of writing, the poor man's abrupt fall has been retweeted over 1700 times.

Oh dear.