Ponca City, We Love You writes "Medieval architects only got as far as the third floor of the tower of Pisa before it began to lean in 1178 and by 1990 it had tilted more than four meters off its true vertical, with conservationists estimating that the entire 14,500-ton structure would collapse "some time between 2030 and 2040." Now the Leaning Tower of Pisa has been stabilized and declared safe for at least another three centuries after it was anchored to cables and lead counterweights while 70 tons of soil was removed from the north side — away from the lean — and cement was injected into the ground to relieve the pressure. The tilt has now returned to where it was in the early 19th century and architects say there was never any intention to straighten the 56m tower, only to stop it sinking further. Nicholas Shrady, author "Tilt: A Skewed History of the Tower of Pisa" says that the tower was destined to tilt from the outset because of the decision to build the tower "on what is essentially a former bog" and that the tower has previously come close to collapsing in 1838, 1934, and 1995. Although Galileo Galilei is said to have dropped cannon balls from the tower in a gravity experiment, Shrady says the myth is the "result of the overripe imagination of Galileo's secretary and first biographer, Vincenzo Viviani.""