In 1990, the Italian government enlisted top engineers to stabilize Pisa's famous Leaning Tower. There'd been many attempts during its 800 year history, but computer models revealed the urgency of their situation. The tower would topple if it reached an angle of 5.44 degrees— and it was currently leaning at 5.5. What gives the tower its infamous tilt? Alex Gendler explores the monument's history. [Directed by Aim Creative Studios, narrated by Addison Anderson, music by André Aires].

Alex Gendler: Why doesn't the Leaning Tower of Pisa fall over?

Why doesn't the Leaning Tower of Pisa fall over?

Ancient Romans combated marshy land with stone pillars, but Pisa's architects underestimated, leading to the tower's precarious lean.

A century-long construction halt saved the Leaning Tower of Pisa, allowing the soil to settle and preventing an early collapse.

Leaning Tower of Pisa's infamous tilt began in 1173 due to inadequate foundation on marshy soil, risking collapse at 5.5 degrees.