Pedro Volta, an escape artist from northern Spain, was paying tribute to Houdini at an international magic festival near Madrid by trying to get out of a water tank while wearing a strait jacket. In the video, it's not clear at first that he is struggling, but he later told reporters that he had trouble with a buckle to release his arms. "I made an effort and managed to release the buckle but the energy and oxygen used in doing so was too much."
It wasn't until he lost consciousness and his body went limp that onlookers realized he was in serious trouble and people rushed to rescue him. Once they lifted him out he quickly regained consciousness.