The man fired the shots while in the bathroom of the East 67th Street facility at around 8:45 p.m. Thursday.
No one was struck.
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The man would not come out of the bathroom for three hours.
Police finally talked him out just before midnight, and he was taken to Bellevue Hospital for evaluation .
He brought the gun into the hospital, where he is a cancer patient. Police recovered the weapon.
During the three hour standoff, patients and staff were moved to a different part of the building.
People were asked to avoid the area amid a large police presence.
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