Russian authorities have launched a criminal investigation after a father-of-two plunged to his death in an inflatable ball called a zorb, according to reports.
Denis Burakov, 27, suffered serious spinal injuries and died on his way to hospital after the zorb veered off course and began rolling down a mountain in Dombai ski resort.
His friend, Vladimir Shcherbakov, 33, suffered a concussion, cuts and bruises and remains hospitalised.
An eight-minute phone taken on Burakov's phone by one of his friends showed the two men being fitted into harnesses inside the zorb.
The ball was then released to roll down a hill with the two men inside.
However, the zorb went off its intended path, a man waiting for it at the bottom of the slope tried in vain to catch the ball before it plunged down a gorge.
A man's voice is heard on the video saying, "it's gone in the wrong direction", before screaming "hold it, hold it."
The Emergencies Ministry said both men were ejected from the ball as it tumbled and they landed on the snow about 30 feet apart.
They were rescued by two skiers, who then pulled both men up to the top of the hill.
Sergei Loginov, deputy director of Z-orb.ru, the largest supplier of zorbs in Russia, said the zorbing run that killed Burakov was "an experiment on life."