Oil behind my pulley?! Help!!!

Any ideas what happened here?! My truck started to make a high pitch siren noise a couple days ago and today I just saw this? This is right behind my pulley. Sorry, I don't know the names of the pulleys.

 

Check your powering steering fluid. If it's low, it's probably the power steering pump or a hose.

 

My power steering is good still. I just looked around some more and noticed all my coolant is gone?!

 

Could be a leaking hose. Hard to tell from that pic. Maybe a water pump

If the serpentine belt is a little loose from age it might start squealing from being sprayed with coolant.

Good luck with this!

 

You sure that's oil? If you're low on coolant, it could very well be a failing waterpump, as the leak appears to be right below the pump.

 

Yeap, I think @cheech1 is onto it. Probably the water pump. Can you smell coolant? Like kind of a sweet smell when your engine gets hot?