Liu Penqan

Liu Penqan was a Chinese who wounded 13 people with an motorcycle helmet on an unidentified hotel in Acheng District, China in 1976.

1976 event
In 1976, when the guests were sleeping, Liu got up of his bed, put an blunt motorcycle helmet on his head, and began headbutting sleeping guests, causing some to lose their consciousness. After wounding thirteen people, he died after he had an stroke from the impacts on the sleeping people.