When I was 10 (decades ago), a classmate drowned in our neighborhood park (he was playing in a drainage ditch after a rainstorm and the flow of water trapped him against an intake screen covering a pipe).

The park wasn't closed, no one was banned from the park, us kids were all strongly warned by our parents from playing near the ditch in the rain.

Problem solved, no one died there in the remaining decade we lived near the park. They did put up bigger warning signs, but other than that, no changes were made until quite recently when the park was redeveloped and the drainage was moved completely underground.

Though I guess this is an argument both for and against "free range parenting" -- kids will do stupid stuff when they are not supervised and sometimes that stuff can get them killed or injured, but also they are able to look after themselves if they know the dangers out there. I only remember 2 other deaths in my school classmates - one died in a traffic accident on vacation with his parents, the other died after complications during wisdom tooth extraction (that one happened 2 weeks before my own wisdom tooth extraction, I was pretty worried).

In contrast to today's risk adverse society, a couple years ago a child injured himself on a wooden play structure (cut his arm on some split wood badly enough to need stitches). The city fenced off the structure for a year until they replaced it with a "safe" plastic structure.

I think that most serious dangers are pre-wired into us, most kids will avoid them.

From my perspective of raising kids, they aren't pre-wired but learned, with most kids learning them somewhere between the ages of 5 and 10.

Few months ago two boys playing alone outside drowned in cold river (in my locality). Nobody knows what happened, their bikes were found near river and bodies downstream.

River is not in bottom or dangerous canyon and look like normal river. Which is dangerous in cold weather, despite not looking dangerous.