Locally we recently had a 9 year old girl die while skateboarding in front of her home. Like the vast majority of fatal skateboarding injuries, she was run down by a motor vehicle right in front of her home. The article didn't say whether she had a helmet on, it wasn't relevant.

It's what kills most kids on bicycles as well. I myself witnessed 2 children die on separate occasions because they were run down by cars. Automobiles and firearms are the leading killers of children.