CITI UNDER SIEGE. I dropped quickly by the Citicorp Center at lunchtime. The Atrium is closed, so only the shops facing the streets seem to be in business; Barnes & Noble and Houston's had what appeared to be a normal amount of traffic.

There were a few cops on each corner and at each entrance -- not as large a force as you might expect, but even one New York City cop carries a lot of weight on the street, and who knows what less-observable presence NYPD has going on.

The surest sign of the change in status was the presence of media trucks parked along Lexington. Most of their crews seemed to be in downtime, lounging on canvas folding chairs when I came by, though one cameraman was patiently recording a cop who held the leash of a panting, happy-looking German Shepherd.

A lot of passers-by seemed, like me, to be gawking a little as they shuffled past, interested in how the City was playing this one. "I can't believe this has become a tourist thing," one guy said.

On the subway steps was a paper seller with a pile of the Daily News, each front page featuring a picture of the Citicorp Center and the word TARGETS.

Just another day.