Trauma sucks. The things that cause trauma suck worse, imo.
When I was a little kid - like, under 8 - I lived in a small house, on a relatively quiet street with my folks and older sibling.
It was an average house. Cramped kitchen, tiny dining room, three meh-sized bedrooms, you get the idea. We had this stupidly long driveway that was great for two kids and their bikes, relatively even, no major slope or anything.
When I was maybe six- I think I was six- my sibling was an idiot and ignored my warning about biking towards the family car (a large, beat up white minivan, rust on the edges and interesting rocks in doors and inside pockets, with three rows of seating).
There was a lot of blood and a lot of crying. If i was 6 than this was when they were like 7, a few months before they would turn 8.
I'm pretty sure both my parents came out to see what happened, but my mom went inside with my sibling first to get all the first aid stuff and call her folks in case they needed to take the sibling to the ER.
My dad was supposed to bring me inside- make sure the younger child wasn't injured or too terrified or anything and everything.
Long story short my dad locked me outside for a while, slammed the door in my face and all that jazz. I could hear the crying and lots of panicked talking through the living room window right next to our door. But I guess they couldn't hear my knocking.
My dad sure as hell didn't tell my mom he'd left me out there.
I gave up pretty quickly. I'd had my dad do things like that to me before, so I wasn't terribly surprised (he would continue the trend of locking me in or out of places as I got older, the 4th of July when I was 9 or 10 is especially memorable).
I sat outside for around an hour before the he came out to get me, chastising me for not being inside, "like I was supposed to be."
I didn't bothering arguing. They were too busy bustling out the door.
He knew what he'd done, he locked the door in my face, I'm not sure if I imagined him meeting my eyes through the window as I watched them clean the blood off my siblings face in the living room.
I don't really remember if they dropped me off or if I got picked up to go to my grandparents, that day got a little hazy after the door was finally unlocked. But I was at their house until late into the night, a bit past midnight.
Probably one of the mildest childhood memories I'll share, but I was terrified of blood for years after that, and I always hurried to be the first person inside until we had to move a couple years later (a story for another day).
Overall, I think my sibling was a helluva lot more traumatised after that day, would hardly touch their bike for weeks afterwards. Self conscious as hell about the scar it left as well - little me was jealous that they had a cool scar, I don't think that helped with their anxiety.