Then, in 1989, a similarly constructed bell tower in Pavia, northern Italy, collapsed suddenly.Īrmed with a plan, workers went to the site and wrapped steel bands around the first level to prevent the stone from fracturing.

None of these measures succeeded, and slowly, over the years, the structure reached an incline of 5.5 degrees. They also caused future preservation teams to be more cautious, although several engineers and masons studied the tower, proposed solutions and tried to stabilize the monument with various types of bracing and reinforcement. The tower began to lean even more precipitously. To seal the base of the tower, workers drilled a network of angled holes into the foundation and then filled them with cement grouting mixture. In 1935, engineers became worried that excess water under the foundation would weaken the landmark and accelerate its decline. These measurements revealed a startling reality: The top of the tower was moving at a rate of around 1.2 millimeters (0.05 inches) a year. Careful monitoring, however, didn't begin until 1911. Finally, between 13, workers finished the project, once again trying to correct the lean by angling the eighth story, with its bell chamber, northward.īy the time Galileo Galilei is said to have dropped a cannonball and a musket ball from the top of the tower in the late 16th century, it had moved about 3 degrees off vertical. The rate of incline was sharpest during the early part of the 14th century, although this didn't dissuade town officials or the tower designers from moving forward with construction. Unfortunately, the building continued to settle, sometimes at an alarming rate. Engineers tried to make another adjustment, this time in the fifth story, only to have their work interrupted once again in 1278 with just seven stories completed. Soil under the foundation continued to subside unevenly, and by the time work resumed in 1272, the tower tilted to the south - the direction it still leans today. The tower sat unfinished for nearly 100 years, but it wasn't done moving.

Leaning tower of pizza delivery area