While I was driving my engine went dead. I had been low on gas, so I thought I might have run out of gas. I filled the tank about half full, however my car still wouldn't start. I tried turning the engine over a couple dozen times, but the engine wouldn't catch. I tried to both pump the gas pedal and hold it down, niether had any effect on the cars audible attempts to start. What could be wrong?

Optional Information:
1995 Honda Civic