Hollywood put its business on hold on Tuesday in the wake of the terrorist attacks on the East Coast. In addition to the cancellation of Tuesday’s scheduled Latin Grammy Awards ceremony and Sunday’s Emmys telecast, Madonna canceled her concert at the Staples Center (some 20,000 tickets had been sold) and most of Tinsel Town’s major studios closed their doors. “We’re in lock-down mode and on high security,” Lee Zeidman, senior vice president of operations for the Staples Center, told Reuters. He said the pop diva’s Thursday and Friday concerts were still scheduled to go on at this point. As for the studio closings, staffs at AOL Time Warner Inc.’s Warner Bros. (AOLTW also owns PEOPLE), Sony Corp’s Sony Pictures (which owns Columbia and Tristar Pictures) and Vivendi Universal’s Universal Studios were instructed to go home on Tuesday. Disney employees were reportedly given the option to leave. The major TV networks also canceled regular programming to allow for blanket coverage of the events. (Even MTV canceled its regularly scheduled programming to carry live CBS coverage.) NBC said that production has been halted for the week for its popular late night programs hosted by Jay Leno and Conan O’Brien. The last time anything similar to this type shutdown occurred was on Nov. 22, 1963, when President John F. Kennedy was assassinated.