A recent published article had a great story of how ice-flow modellers saved the day!
“Last year, a large, water-filled pocket in the Tête Rousse Glacier of the French Alps threatened to burst and flood the valley below. On an urgent request by local authorities, scientists quickly developed a model to assess whether draining the cavity would weaken the cavity roof and cause it to collapse. The model accurately predicted that draining would be safe.” Nature Research Highlights
The subglacial cavity contained at least 50,000 m3 of water. Here is a great video of people climbing into the inside of the cavity after it was artificially drained.
Another video (in French) details how they went about draining the water from the glacier.