Steam Pipe Explosion?

Steam released, creating hole in street. The minutes after it happened, people were frightened, scared, panicky, not knowing what just happened. Also in those moments, the mayor and other city officials quickly approached the microphones to calm the masses. They were hasty to point out that this event was not terrorist-related. My question, and the question that everyone should have, is how could that be known as a fact so soon after the tragedy? The situation could not be properly assessed that fast, could it? I don't think so, especially with so much damage done. Sure, it is a steam pipe that burst, but the why is the mystery. Cold water into the system? From where and by whom? Transformers blown. How? The steam? I would like these questions answered, really. The mainstream media needs to stay up on this story, don't let it die out. New York is a decent city and the truth needs to be known. Reporters should do what they got into the business to do: investigate and report. That is all.