What’s the rationale for removing “urban violence?”
Because urban violence is almost entirely driven by gang and illegal weapon crime, not by accidental or unintentional deaths (which your quoted article ignores in the study it refers to). Any legislation suggested by you, the article or any other uninformed-on-the-subject nitwit, would have no effect on the reduction of these types of deaths. Criminals won't give you their guns because you legislate it so.
So if you really want to discuss how legislation can effect unintentional deaths of children you need to focus on what would be effected with any legislation. But if you do that, the massive and glaringly large statistic where children are killed with guns (not by gangs or suicides) becomes almost non-existent.