When I turn the key, I hear a single clank like metal on metal. I'm assuming the noise is the bendix is trying to engage the flywheel, but not able to.

Does anyone know what the problem is?

 

My first thought would be that the way most starters die is one of two things, either the solenoid quites and you get no sound at all...or you get the single click which is the solenoid moving to engage, but the motor has poo'd the bed.
Do all of your other accessories work? Just want to check and make sure you don't have an almost dead battery causing the issue. Or a failed alternator, once you get it started.
If you have a manual trans, you could try the old rolling clutch start method. If you have an auto... you could aways check the battery with a multimeter, or in place of that, a jump start attempt.

 

Hey RocketMouse, thanks for the advice. That's kind of what I figured.