Bringing this topic up in the context of the latest school shooting in Wisconsin
Article with some data for 2024: https://www.abc.net.au/news/2024-12-17/us-school-shootings-2024-in-numbers/104734714
The vast majority of those gun related deaths are accidents with parents’ guns at home.
That really depend on the age of the child in question. According to the statistics as they get older it really tilts to suicide and criminal / gang violence.
The biggest step parents can take to prevent all of it though is pretty simple; secure your firearms so that children cannot access them.