When I was like 3 or 4 my brother and I were jumping on our dads bed and he pushed me straight into a sharp bed corner which made a giant gash on my forehead.
Another time was when I raged on minecraft and I slammed my monitor downwards which popped out the glass and cut my wrist. It gushed blood every where and I could've cut an artery which I would've died in minutes. Unlucky for me my parents or my brother weren't home so I wrapped my wrist with a T-shirt until they got back. Thankfully I didn't cut an artery but I couldn't move my wrist/hand for the next couple of days.