in 1999, I was working on a construction site that utilized a 1000 ton crane - this meaning it could lift 2 million pounds of a load adjacent to the crane. The longer the reach, the less the capacity due to the leverage. We were installing tube bundles that weighed in excess of 300,000 pounds each with a horizontal reach of about 150 feet. This was judged to be safe, for a lot of calculations are performed before such a lift is attempted, and a machine that size requires a crew of eight.
All was well and several bundles had been installed, when the cabling snapped. These cables, about 4" thick, are used to support the enormous boom as well as lift the load. When it failed, the boom crashed to the ground, destroying the boom and damaging a lot of equipment, with a close call since it fell next to a junction of several high pressure fuel gas lines. Luckily, no one was hurt.
The crane failures shown in the embedded video (and Youtube features many such videos) are maybe not quite so dramatic but are nonetheless awe-inspiring to watch. If you've ever worked construction, you know what I am talking about. And if you've merely watched cranes in action from afar, maybe you'll appreciate just how dangerous this work can be.