driving to work, heard light knocking under hood when accelerating. Thinking it needed oil, I was headed to the store after work and the truck shuts off. Big pool of fluid underneath. Tow truck driver said it was oil. I took this picture to see if anyone can tell me what this is. I looks like something from the inside shot out and all the fluids came with it. The pic is upside down. I can't even tell you what part of the engine that is. I know the metal is pulled back so something shot out of there pretty darn hard. Truck will not crank. One click, that's it. Is my engine locked? Please help