USS Enterprise, summer of 2001. The scoop inlet to our main steam condenser had been clogged up with seaweed or something, so we were going to backflush it with the very, very large seawater pump that we operate at low speeds to keep water flowing through. This operation involved bracing a giant check valve open with a large bar and some chain, then turning on the giant pump. Normally, the check valve would automatically close, but this action would leave it open so it could force the crap out from the scoop.
So I was holding this bar up so my friend could attach the chain. Heard the distinctive whine of the seawater pump turbine spinning up, and before I could do anything, the force of this 25,000 gallon per minute seawater pump slammed that 48 inch check valve shut, resulting in that bar I was holding slamming to the ground. Nearly on to my foot. As it was it was just to the side, so it pushed my foot and cracked a single bone. Had my foot been 2 inches to the right, it would have driven straight into the center of my foot, just where that angle is where the ankle turns into the foot, and completely crushed all of it.
I know this because the force of the bar bent the 1/4 inch steel deckplate. 
Granted, its not a ‘I could have died!’ story, but I’ve no doubt I would have either lost my foot, or walked with a severe limp for rest of my life.
Another one… Dad is scared of heights, and I’m not, so he always has me climb to the top of our grain elevator in the spring to grease the fittings and make sure all the flow diverters operate freely. I don’t mind, and we have an agreement that I climb stuff, and he goes into spider infested holes. So i climb up the rickety ladder on the side, do the greasing, but one of the flow diverters is stuck. No problem, brought a bar specifically for this. Pull on bar… wow… that thing is really stuck. Lean into it. Nothing. Beat on it some, lean into it some more… a little more… a little more… CRACK! The thing breaks free, and I go flying backwards, over the low crappy rail, and fall 3 feet before being jerked to a stop by the harness I was wearing. See, the year before, I had finally convinced dad to spend a few bucks on a safety harness to wear while up there, considering its 80 ft off the ground. I pulled myself back up, and sat shaking(and vomited) for 15 minutes before I could climb down again. Found dad and told him that was the best money he ever spent.