Here are a couple from a place I used to work. The guy in the background wearing the blue hood was the operator. In all fairness, it wasn't his fault entirely. He was told by an engineer that it was safe to walk through there, he pretested and was told by the superintendant to do it.
He wasn't stuck as bad as this at first, but the same superintendant decided to dig around it to pul it out. They didn't have neough power to pull it out and the machine sunk further before the hole collapsed around it. So the not so super-intendant said "Well, that didn't work....do it again!" They did, and the same thing happened again. That's how it got in so deep. It took us 18 hours to get it out using two TD25's, an 850C, PC200LC, 892E LC, and an EX700 LC. We were all filthy by the time it was over.