As a demonstration, an instructor had a block of ice suspended between two chairs. She then hung

Question:

As a demonstration, an instructor had a block of ice suspended between two chairs. She then hung a wire over the block of ice, with weights attached to the ends of the wire:

Later, at the end of the lecture, she pointed out that the wire was lying on the floor, apparently having cut its way through the block of ice, although the ice block remained intact. Explain, by referring to the phase diagram for water (Figure 11.11), what has happened.
Figure 11.11
Phase diagram for water (not to scale)