Lost Serpentine Belt

[NickNickNick]

Hi.

Today I was on the highway, travelling about 100km/hr when I noticed my temperature guage came on. That had never happened before, so I pulled over to check things out. The coolant was definitely hot, so I let the car sit for about 15 minutes or so (I also had the a/c blasting, as it was about +35c outside). I started the car up, kept the engine at 80km/hr and about 7km down the road, could begin to smell coolant. I pulled over again, popped the hood, and the coolant was boiling over. I noticed at this time the battery light also came on, as did the check engine light. I also noticed that the temperature guage had gone from too hot to reading "cool." I shut the car off, let it sit again for 15 mins, added some coolant, and tried to start the car. Wouldn't start. Electrical is all fine, but when trying to start it made a high-pitched noise. I popped the hood again, and noticed that my serpentine belt was gone. I must've drove about 10kms without it before noticing. Any idea what that'll cost to fix? Assuming all that is needed is a serpentine belt. I checked the oil and coolant immediately after noticing the missing belt, and there was no coolant in the oil, and no smoke coming out of the exhaust, so I assume everything else is alright. There were also no fluid leaks anywhere, other than the boiled over coolant (the rest of the coolant stayed in the casing), as I had plenty of time to check waiting 2 hours for a tow truck in the middle of nowhere, Saskatchewan. I have about 127,000km on my 2006 Yaris.