Wow, that looks more like a blown nitro engine damaged from a missed tune up. Mere a fraction of a second I guess from blowing the entire crank and pan right off the car.
Seems like severe denotation but if so, then the pistons would show maybe collapsed top ring lands and other issues. Odd that the pistons, rings, rods didn't show some extreme stress. If not, bet the cracks started slowly and only over time widened to what is depicted. Ouch, indeed!