ok so i asked chatGPT:
How deep are the remains of the Titanic?
> 3.800 meters (12,500 feet)
What is the water pressure at that depth?
>38.000 kpa, or 400 times the atmospheric pressure at sea leve.
If i had a theoretical object that could make such pressure at sea level, how much that object should weight?
>After some calculation, the result is that the object should weight 3877 tonnes (17,623,636 big macs)
That pressure is being applied in all directions underweater.
But, we have to take into account that the sumersible apparently didn't reached that depth before being squashed.