MOSCOW (AFP) - A Russian man died after burying himself alive in a friends garden in the Far Eastern city of Blagoveshchensk in an endurance test that went wrong, an investigator told AFP on Wednesday. According to his friend, the man, 35, 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 regions chief investigator. The two men dug a hole in the garden and put inside an improvised coffin with holes for air pipes. The man also took a blanket, a bottle of water and a cell phone. The victims friend told investigators he covered the hole with planks and earth to a depth of around 20 centimetres (eight inches) and then went home, after receiving a phone call from his friend telling him he was fine. The next morning, he found his friend dead. Lubinsky speculated that a rainstorm overnight could have blocked the air supply to the coffin.