Well, I would think you crushed the exhaust pipe in the wreck rather than the engine sucked it in to a crushed state. The fuel line was probablly stiff from the engine running all crazy and over heating the fuel line causing it to get brittle, I would think, only logical thing I can come up with. The hissing was probablly fuel boiling off the over heated engine from it running at such high rpms with nothing to stop it from running as fast as it can.