The most likely problems that could cause an engine to die of would be:

1. Faulty safety neutral switch.
2. Loose or corroded battery cables.
3. Dead battery

Step 1
Set the emergency brake.

Step 2
If you are using automatic transmission, turn the key while holding the gearshift lever firmly in the park position. If nothing happens, try again with the lever in neutral position. If using a manual transmission, be sure to push the clutch pedal all the way to the floor. If the car starts up after any of these steps, a faulty safety neutral switch causes the problem. If the engine refuses to turn over, remove the keys from the ignition and follow these next steps.

Step 3
Tighten any loose battery cables. When tightening the positive cable, ensure that you are not touching any metal while the wrench is connected to the cable. This will help avoid arching, which could damage the battery.

Step 4
Check for corrosion where the battery cables connect to the battery. If you see signs of corrosion, remove the battery cables beginning with the positive side. Now, clean both the inside of the cable end and the battery post using a wire battery brush. Do not reconnect the positive cable until the negative side of the battery has been cleaned.

Step 5
Reconnect the red battery cable to the battery post marked with a "plus" (+) symbol.

Step 6
Reconnect the black negative cable to the battery post marked with the 'minus' (-) symbol. After completing these steps, try to start the engine. If the engine still refuses to turn over, the battery will need to be jump-started.