The cause of the accident was not the dropping of the crane’s feet. Witnessed coworkers said, when crane truck parked on the roadside, the driver put down which are the two support feet on the right, while the left side support feet did not put down the tripod, the crane suddenly tilted to the left,One worker immediately unlock the safety belt and timely escape on the tree, another worker will unfasten his safety belt ready to escape, when a driver saw crane tilted, hurried to down the left side of the support frame so that the crane suddenly rises in the opposite direction, a worker on the lifting platform lose his balance and fell from ten meters high and he was certified dead on the ground.