The Sistine Chapel closed to visitors Tuesday and construction work got under way to prepare it for the conclave. Five cardinals, however, remained AWOL from the preparatory meetings to discuss who should run the Catholic Church following Pope Benedict XVI's resignation. The Vatican insisted nothing was amiss and that the five cardinals would be arriving in the coming days. But their absence prompted questions about what could possibly be more important than participating in these days of discernment and discussion to decide who will succeed Benedict, who retired last week. Those still making their way to Rome were Egyptian Patriarch Antonios Naguib, and Cardinals Karl Lehmann of Germany, Jean-Baptiste Pham of Vietnam, Kazimierz Nycz of Poland and John Tong Hon of Hong Kong, the Vatican said.