crank no start: no codes, no fuel at primer, rattle from engine

These trucks have an injector pump that's driven off the main timing gear. It's in the front of the engine in the valley. So if you heard noise coming from under the hood or front before it stopped running and you have no fuel pressure now while cranking it sounds like your injector pump took a crap. What u can do to verify lack of fuel is get a small rag and wet it with gasoline not diesel and hold it infront of the throttle body. My buddy has a twin turbo duramax and I've helped him pull the motor a few times and he's showed me a few little tips n tricks. A few drops of gas should start it up. U also can check the fuel rail for pressure with a gauge but if u don't have 1 on hand the gas rag can confirm no fuel.

broken crankshaft...