the answer:
Though it's on the small side, if you look closely at the picture you can just make out a panoramic view of Midtown Manhattan behind the blissfully unaware subject, indicating that the photographer is facing north. Only one of the planes that hit the World Trade Center on September 11 approached from that direction: the first, American Airlines Flight #11, which struck the north tower (One World Trade) at 8:45 a.m. The trouble is, the north tower had no rooftop observation deck such as pictured here. Even if it had, it wouldn't have been open to tourists at that hour.
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