Subscribe | UPI Odd Newsletter Subscribe KIRKWOOD, Mo., June 2 (UPI) -- A Missouri high school graduation ceremony involved all 437 graduates performing a dance routine to the Black Eyed Peas as their senior prank. The graduates of Kirkwood High School in Kirkwood said administrators approved the senior prank and two girls from the pom squad taught the dance, which ended with the traditional throwing of hats, to the graduating class the Sunday prior to Saturday's ceremony, KPLR-TV, St. Louis, reported Wednesday. Advertisement The students said school administrators sent a letter to parents informing them of the plans, but grandparents and others at the ceremony were surprised by the flash mob-style dance. "I was kind of worried that not everybody was going to do the dance," graduate Annie Diven said. "Then it wouldn't look right."