Somewhere a redditor did the math and I believe it would have taken 24ms for the glass to break and the water to rush in. Instant death if it was indeed the glass.
Guillotined people can still be alive and feel about 30 second safter their head has been removed from their body.
Imagine a Ford F150 sitting on every square inch of your body.
I don't think there will be any bodies to recover.
logically not in this case. at that point where the water level is sufficient to make someone drown the remaining air would be compressed to several hundred atmospheres pressure.
And because making sounds without lungs attached to your throat is kinda hard
Similar to the Arbogast in The Expanse, but even greater disassembly.