I and scores of others witness a silver pyramid spinning in place abourt 50 feet above the school yard.

Public School 54's grounds at lunch time. I came out into the school yard for recess, saw with about 50 other students, including some faculty members, a silver pyramid appproximately the size of a small school bus spinning in place about 50 feet above the school yard. The object made no sound. This was no optical illusion because the sun's rays reflected off the pyramid's metallic surface. A few minutes into my observation, a helicopter arrived and immediately flew around the pyramid. The assistant school principal, also witness this event. He remarked something about UFOs, and this was the first time I ever heard the term. The school bell sounded, signaling the end of recess, so I went back in. At the end of the school day I came back out, but both the pyramid and helicoper were gone.
 This is my second posting---it is as if either I'm not being believed, or someone wants to censure me. There are no news reports about this incident, but I know there are others out there that witness this event, so please come forward!
Date is approximate.  Source apparently submits report from prestigious university, but elects to remain anonymous.  PD