I’ve done my University project about Diamonds and i read this before.
Take a look at the National Geographic’s presentation for more detail. It said a truck would take about TWO Hours to surface from the bottom!! and people would work under the tempreture of -50F to -70F.
http://www7.nationalgeographic.com/ngm/data/2002/03/01/sights_n_sounds/media.1.2.html
It shows on Part 4, Extreme Mining
