I would guess a belt. Example: Your air conditioning compressor bearing/alternator bearing failed and the rotor won’t rotate . Your belt smoked. Or timing belt. Just a guess.
Yes, I would agree it sounds like the serpentine belt burnt then snapped when something seized up. The No 1 suspect would be the air conditiong comprssor, No. 2 the idler wheel. After that, I assume the car overheated since the water pump wasn’t working because the serpentine belt broke, and that may have lead to a warped or cracked head.