A Russian man has died after persuading a friend to bury him alive for a night, hoping it would bring him "good luck".
The victim dug a hole in a garden in the eastern city of Blagoveshchensk and climbed into an improvised coffin, with holes for air pipes, taking a mobile phone and a bottle of water with him.
His friend covered the coffin with earth and then left, after the buried man phoned to say he was fine.
The next morning, he returned to find his friend dead, investigators said.
The 35-year-old victim had believed that burying himself alive for a night would bring him luck the rest of his life.
"According to his friend, the man wanted to test his endurance and insistently asked his friend to help him spend the night buried," said Alexei Lubinsky, a senior aide to the region's chief investigator.
"We know that the victim was a computer programmer and that he has a small child."
The coffin was covered with soil to a depth of about 20cm (eight inches), Mr Lubinsky said.
He speculated that heavy rainfall overnight could have blocked the air supply to the man trapped inside.
The superstitious victim was probably influenced by reading stories about self-burial on the internet, investigators said.
In a bizarre trend, numerous Russian bloggers write of undergoing supervised self-burial. State newspaper Rossiiskaya Gazeta has even run a feature on the practice.
The BBC's Steve Rosenberg, in Moscow, says it is not the first time this has happened in Russia.
Last summer a man in the north-western Vologda region persuaded his friend to bury him in the ground - to help him overcome his fear of death.
He was found dead an hour and a half later, crushed by the weight of the earth.