There is a method of execution known as pressing, which was the crushing of someone under immense weight. One famous example occurred during the Salem witch trials where a man, not a woman, got so sick of salems bullshit that he refused to talk when questioned and so the town tried to get a confession out of him by stacking rocks on top of him, with the only response being "more weight". He eventually died from the crushing pressure of the rocks. Another famouse example involves an elephant crushing a person, though it was common to crush the limbs then the head.

How is this known?

Scale in mouth, bite?