[PGR88]

I also agree its not shells from a destroyer

Look at the clustering. Also, look how the “spray” or movement generally flows outward from a generally central point.

I would guess someone rolled up an M5 anti-tank gun on the thing at close range and started blasting away

[ProtectOurFreedom]

“someone rolled up an M5 anti-tank gun on the thing at close range and started blasting away”

Maybe after the war was over and they were disposing of thousands of tons of surplus ammunition. Certainly not DURING the war.