I almost got killed twice trying to drill the same well when I was 18ish. My dad and I were trying to drill a well in a pasture on a hill that was a little steep, but nothing more that we'd done before. We drove the rig out the evening before we planned to drill it, only it rained for 2 straight weeks and we couldn't get back out to it.
When we got back out we leveled the rig by putting railroad ties under the jacks, but the ground was a lot softer than we thought and the rig settled slightly uneven. We kept the 300 pound steel tank on top of the mast when we laid it down so that when we raise up the mast it was hanging from the boom. My dad didn't know I was on the low side and started raising the mast. As he raised it the box swung off to the low side and the corner of it caught the back of the shirt. If I was standing 6 inches back the corner would have taken out my side.
At that point we decided to wait a week for the ground to dry. When we went back we releveled it, but had about 6 railroad ties pushed into the ground under each hydraulic jack. We waited 30 minutes for it to settle, but it was still level so we start. Right before my dad started to drill, again I was on low side, and the low jack slipped off its railroad ties. The rig started to roll towards me, however the tires dug into the ground and kept it from rolling completely over. It sat tilted for about 10 seconds before it fell back upright.