[PLMerite]

Looks like maybe 75mm from a Sherman, but that’s an unsupported guess.

And, yeah, I bet it was LOUD inside. At least until the flamethrower guy got there.

[L,TOWM]

Some of the smaller ones could be 40mm or Ma Deuce hits, too. But yeah, with the guy next to the structure, it sure looks that thing got hit by quite a few 75 or 76MM Sherman cannon shots.

[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

[Rockingham]

Or the same caliber on a Churchill or Cromwell tank. That the hits on the turret are on the landward side excludes naval gunfire.

[Calvin Locke]

Odds of any spalling?