The engine isn't turning over at all. I've had problems nearly identical to this before when it's been cold out, where the engine will try to start but won't catch. Overtime as I would continue to try to start the engine, it would make less and less of an effort, until it wouldn't even turn over, just like now. In the past, plugging the block heater in has always fixed this problem, so I assumed it had something to do with the fuel.