Two occasions where I have come close, both due to other people:
1) One of my friends in secondary school invited me down to his house, where he was shooting at targets with his dad's air rifles with one of my other friends at the time. Was walking down his drive when one of them aimed the air rifle at me for a joke. Bearing in mind, we were about 13, so anything could have happened. He laughed and reassured me it wasn't even loaded, then turned around and shot at the target. Basically, if his finger had slipped or something, I could be dead. Let's just say...he was a hard one to trust.
2) This one happened on a family holiday two years ago. We were on a French motorway, and decided to stop for lunch two hours into our six hour drive to our holiday home (not ours, just one we were renting). My dad is a fast driver, my mum is a slow driver yet a hell of a lot safer. We all wanted to get to our destination, and my mum offered to drive. My sister expressed how she believed we'd get there a lot faster with my dad driving, and my mum just agreed and let my dad drive.
Two hours later, I was reading and my mum and sister were listening to the radio as my dad drove. Suddenly, my mum and sister both screamed, as the car bounced off the railing at the side of the motorway and my dad stopped the car as quickly as he could. As it turned out, he had fallen asleep at the wheel doing roughly 60-70mph, maybe more. We were lucky there was a metal railing where he crashed, because ten metres further and we would have ended up in a ditch, probably not getting out of it unhurt like we had done. My dad then decided to tell us that he gets tired driving after having lunch, which was really helpful to hear after he had dozed at the wheel.
The rest of the holiday was spent shouting at him to slow down when he went too fast, which was fairly often. He would shout back, clearly not learning his lesson from the crash which has now kinda made me nervous getting into a car with him.