Just when swine flu was fading from headlines, the assistant principal of a high school in Queens, New York has fallen prey to the disease. Mayor Bloomberg said today the man, who is on a ventilator in critical condition, may have had “pre-existing conditions” that made him more vulnerable to the H1N1 strain. Officials have closed his school as well as two others in Queens with groups of students and teachers exhibiting flu-like symptoms. The schools will remain closed for a week. So far there have only been three deaths out of 4,298 cases of the flu in the United States, and the disease had begun to fade out of the news cycle.