we were walking on a lake we went to regularly in summer and winter and the ice wasn't quite ready for our weight. I fell through (only up to my waist luckily). my dad fished me out and we went home immediately even though we'd just gotten there. I was probably 5 1/2.
I vaguely remember before that a memory of watching a person killed on tv. it was during the Vietnam War, so it was a real thing and it affected my parents so it affected me. That would've been age 4-5. I've seen so many shootings on tv and movies since, it's hard to know if that memory is real or not.