Not my story, but one worth repeating from another site. Helmets are one thing, UTV's and roll cages another.
The short version is that i was going down hill 20% grade on an "S" bend.
Had a full 16 gallon sprayer tank in bed that slammed into right bed side.
RTV went over on drivers side and roof/roll bar landed on my chest on down hill slope.
Broke ribs at sternum and got a grade 5 out of 6 liver laceration. (6 means you're dead).
Broke both bones right forearm lifting rtv off me as I couldn't breathe due to roll bar weight.
Don't remember lifting it off just that i was out from underneath.
Spent a week in trauma icu and 3 months learning to use my reconstructed stainless steel reinforced arm.
RTV is over 10 years old not lifted but has slightly larger off road tires. Never had an accident like this, never been in hospital or broke anything before. Please don't feel bad for me as I'm great now and this near death incident inspired me to get my bucket list going (like leaving the sorry state of calif). As an engineer i would caution you all to consider the COG and the effect of side stability of you vehicles whenever driving. Heavily Padding the seat rails is recommended as well as always wearing your seat belts. I would not transport smaller folks with out belts AND side safety curtains. Lastly I never thought it could happen to me.
If this reminder helps one person avoid this kind of injury I'll be very happy.