A good many things have been dropped from the roof of the Green Building, which is the tallest building on the MIT campus. Usually pumpkins and fire extinguishers. The pumpkins get dropped on Halloween, and the other objects can be dropped whenever one of the undergraduates can find a key that unlocks the hatch to the roof. Other things have been thrown from the roofs of other buildings; the most famous is the piano that was dropped from the roof of Baker House. Things that hit the ground after being thrown off the Green Building tend to go "splat". One fire extinguisher, however, hit the ground headfirst, and the nozzle was blown off by the impact. It was later found partially embedded in the wall of the West Parallel of East Campus.
A great number of new buildings have been added to the MIT campus since I left - ironically, most of them placed there by the company that employs me. I have no idea if anything has been dropped off the roofs of those structures, although I understand from reliable sources that, in keeping with its whimsical geometry, nothing thrown from the roof of the Stata Building falls to Earth in a straight line.