I've never been involved with an engine failure, but we did have one light on fire one night, well, I guess it was a failure, because after it burned it failed to start! We were in MSN (Madison, WI) and we were taking the airplane up to our maintenance base at SAW (the old AFB up near Marquette MI). We had already sent the pax into the terminal, and it was just a ferry up to SAW, no pax. I had an IOE student with me on this particular trip (I was a instructor flight attendant and I'd take new-hires on my trips after they finished training and before they'd fly on their own). I thought it would be good experience for her to watch the pilots start the engines, this was on the ATR, and I was standing in the back by the door, looking forward, and she was up front watching the guys. Over her shoulder I see the #2 engine fire handle lit up, I didn't think much of it, I thought the guys were just showing her the bells & whistles. Then the F/O comes over the PA, and in the blandest, most uninterested voice I have ever heard, he says "evacuate aircraft left". The way he said it, I didn't quite know what to think, so I opened the service door on the right side of the a/c and stuck my head out just in time to see the POOF from the fire bottle go blowing by me. By that time my student was on her way back to the door, and I almost threw her off the plane, we all run off the plane, the captain runs around the right side, I run around the left, and we all just stand and look and the plane. Meanwhile, the poor station agent is jumping up and down yelling "It was on fire! It was on fire!" We had a great conversation with dispatch explaining why we weren't going to go to SAW that night.