Complex sentence: The tower began to lean soon after construction, possibly due to rush to build the foundation and the first body: the southern part of the tower forged faster than the northern part, which caused a difference in the tensions of both sides that inclined the tower.
Split into simpler sentences: The tower began to lean soon after construction, possibly due to haste while building the foundation and the first body. The southern part of the tower was forged faster than the northern part, which caused a difference in tension between both sides, which inclined the tower.