97 buick lasabre issues

I was driving down the road and the rpm gauge went crazy. Then it flat lined at zero. The voltage warning light came on then the car stalled. It then wouldn’t restart. Tried jump starting and tightening the battery cables. After sitting a while after I tried starting it I heard a sound like a demon grumbling I think it may have been a pump of some sort. Any ideas?

Broken timing chain or broken harmonic balancer. The more I think about it, the more I’m inclined to the harmonic balancer.