91 honda civic si 1.6

I have a 1991 Honda Civic Si with the 1.6 engine. Today i was driving around (mostly highway) when i was on the onramp too get onto the hightway i heard a big pop and the car lost all power and wont start. I check the car over nothing leaking but theres a big hole in my muffler. The hole has about 3-4 inch radius.

Any ideas?

Have you checked for a broken timing belt?