Totally apologize, you’re correct and I’m sooo wrongIt's the 100th episode but I don't think it was called frozen.
The ships bottom didn't flatten out though in the scene where it was sledding across the surface of the planet. No doubt that most likely the bottom probably suffered severe structural failure and over time the ship's weight caused the bottom to fail as well.
The episode I was referring to is called “Timeless”.
As to where I came up with frozen, can only speculate? Still wrong though.
The flattened deck info I remember from the conversation Chakotay and harry were having when they were onboard.
KIM: Power grid's been destroyed. Neural gel packs frozen solid. Decks nine through fourteen are now deck ten. They've been compacted.
CHAKOTAY: Looks like they hit the ice at full impulse.
I could’ve bought that the ice had damaged the decks during its long time there (glacial drift and shearing) but the comment Chakotay had about the ships speed leads me to believe the ship slammed into the ice and crushed those decks.
I’m always open to different interpretations or ideas though.