a whole lot of people are going to be killed when an alien spaceship lands in their city and then a bunch of superhumans start fighting over it. I'd expect that the death toll at the climax of this movie is in the thousands.
Given the actual dynamics of buildings collapsing like that I can't imagine what the farmboy from Kansas could have done to rescue more than a few of those folks. He's neither shown to be fast enough nor experienced enough to accomplish that much.
You know, it's becoming clear a little over a decade later that the lasting impact 9/11 has had on popular entertainment is simply to raise the stakes for fictitious disasters. Before then, the collapse of a skyscraper like that was a catastrophe beyond the experience of Americans and the prevention
of it could easily have been the climax of a movie. Now people making movies have to take out at least a couple of big buildings just to demonstrate that the bad guys are really dangerous.