The only thing that presents a persistent risk to children, I think, is motor vehicles and the way they’re driven. Children make mistakes and San Francisco’s tolerance for traffic fatalities is very high.
The number of pre-teen traffic fatalities is the only concern I have when I’m thinking of letting my children walk around because I think the other risks are relatively overblown. Sure we have an occasional Bill Gene Hobbs and the like but I think only traffic fatalities are near certainty.
These are for accompanied children, so leaving a 5 year old to wander is way different than when I was 5 years old. In SF, I’d rate the chance of survival to 12 at under 90% for unaccompanied 5 year olds walking around the city along the range that I used to at that time.
Teens are pretty self-capable in decision making but pre-teens just don’t have judgment yet. I feel like this is a pretty reasonable statistic to match.