That didn't go well

[700rpm]

I headed out this morning for a 100-mile tour with my grandson for IMAD. As I pulled out of the gas station a guy came around a corner and hit my front bumper from the side. No sheet metal damage, but the bumper is torqued and the ds support is pretty bent too. The bumper moved to the right and the ps seems untouched. Fortunately, we both have insurance, I can make a claim. He probably will too, but I'll let the adjusters figure that out. We parted ways, but when I got into my car to start it, the ammeter was pegged on full discharge. I disconnected the battery and checked under the hood, and the spark rod had detached from the distributor, but otherwise everything looked OK. I reconnected the battery and there was no discharge. The battery was pretty weak, though, and I had to coax it some to get it started. Got home OK, but as I pulled into the garage I heard something like a low wheezing sound from the front of the engine. I tightened the exhaust nuts, but the head nuts were good. Water pump and pulley didn't seem out whack, and I couldn't place the sound with a sound stick.

So, what might have caused the wheezing and the battery to discharge? Here are three photos of the damage.