Guyed towers are supposed to stack down onto themselves when they fail. This is what they are designed to do. It's a really bad day if you happen to be in the shack at the base when it happens, though......
The local NBC-TV affiliate station in my college town finally got a spanking-new transmitter and tall tower installation a few miles away some farmland. (Their original transmitter was a peashooter on the roof of a 4-story hotel.)
The tower construction had taken place in the winter and was all but complete. The antenna and feedline were in place. Also in place was the multi-ton “ginpole,” the principal tower erection device, still lashed to the top next to the antenna. The ginpole was scheduled to be taken down in a couple days and the system fired up within about a week.
Then came the ice storm. Many towers in the area perished that weekend, and this new TV tower was among them.
Late in the spring, some friends and I visited the site and talked to the transmitter guy on duty (this was before the automation of large transmitters made on-duty engineers unnecessary).
He told us of the day the tower came down. He was driving in his Beetle down the short dirt drive from the main road to the transmitter building at the base of the tower, when all hell broke loose before his eyes. The tower came down very much like the one in the video on this thread, with guy wires flying everywhere. The tower clipped off a corner of the small brick transmitter building at its base, twisting and displacing the 8-inch-diameter RF feedline in the building.
The antenna and ginpole, lashed together, landed perhaps 250 feet from the base of the tower. They formed a spear that penetrated over 20 feet into the frozen ground. Insurance investigators had excavated a deep swimming-pool-sized hole around them, and left them sticking out of the bottom of the hole. I got some pix of the scene.