The Observer has a story about a retired French army colonel who is soon to make a free fall parachute jump from 25 miles up. In the process he will break the sound barrier, reaching a top speed of mach 1.68 before he opens his parachute 1,000 metres above the Earth. Of course, if the chute doesn’t open, the hole he’ll make will be about 1,000 metres deep.
Well, actually his max speed will be high up and near the earth the atmosphere will have slowed him down to terminal velocity.