Dazed and confused Dick Van Dyke took a terrifying tumble — and friends fear he is facing his final curtain call. On Oct. 2, the 89-year-old “Mary Poppins” star was at the Malibu Playhouse, where he was performing with “The Vantastix” quartet, when disaster struck. “All of a sudden Dick appeared to lose it!” an insider tells GLOBE. “He was disoriented and collapsed. Fortunately, he was able to regain his composure and didn’t need to be hospitalized.” But the fall is just the latest link in a long chain of health horrors for the star. Get the full scoop when you purchase the latest GLOBE.