Alternator or belt? 98 WS6 Trans Am?

-Tonight when I was driving my car the "check gauges" light came on and the voltage meter was going down fast. The signals got slow and the lights started cutting off then the car died while I was driving it. At first I thought it was the alternator but then I remembered the power steering fluid had started leaking really bad and smoking (I'm assuming the burn off of fluid). Could this have cause the belt to slip and keep the alternator from charging the battery? Help! A new alternator is going to cost around $170 and that does'nt include labor.