After the collapse of Campanile di San Marco on July 14 1902 the city quickly decided to start with the reconstruction: "Dov'era e com'era" (= where it stood and like it was). The reconstruction was finished in 1912, so the reconstructed bell-tower now is 100 years old.
A (fake) picture of collapsing Campanile di San Marco by Antonio de Paoli (1902). Nice example of "photshopping" in the early 1900s. On the days before the collapse the tower began to groan, so municipality and citizens were somehow prepared. However those weren't the times of iPhone but glass photo plates and it's unlikely that exactly the moment of the collapse was catched on glass. What exists are montages that illustrate the drama (in which btw no person was killed... however a cat).