The actual EPA pronouncement was that the air and water in NY city were safe (not to warrant an evacuation). They still recommended that first responders and people in the vicinity wear respirators.
Do you know if they recommended it right away or after a few days?
The amount of blame that got pinned on them after the fact was probably pretty unfair.
If I can remember later, I'll come back and post a NASA satellite image showing the particle density that I saved from that morning