1989 300E problems

I was driving my 89 300E last night to a friend's house and everything was just fine. 10 min later I started the car and heard a pop sound. Just then my SRS, battery and light bulb out warning lights turn on in the instrument cluster and then I lost power steering. I was driving for another 10 seconds so I can pull off the road and the temp gauge went from 80 degrees C to 120 degrees C right away. I pulled over and turned the car off. I opened the hood and found that the serpentine belt came off and I could hear the antifreeze boiling in the overflow tank. Also the line from the overflow tank which goes to the outside of the car cracked into 2 pcs. This happened late at night so I could not see anything else. I called a tow truck and they brought the car and I home.

I think the water pump went but not sure. What are your thoughts???? If it is the water pump how do you repair it and is this something I could do at home?

Thanks

Fab