By VICTOR L. SIMPSON, Associated Press Writer VATICAN CITY – Pope John Paul II, the Polish pontiff who led the Roman Catholic Church for more than a quarter century and became history’s most-traveled pope, died Saturday night in his Vatican apartment. He was 84. The announcement came from papal spokesman Joaquin Navarro-Valls and was distributed to journalists via e-mail. “The Holy Father died this evening at 9:37 p.m. (2:37 p.m. EST) in his private apartment. All the procedures outlined in the apostolic Constitution `Universi Dominici Gregis’ that was written by John Paul II on Feb. 22, 1996, have been put in motion.” A Mass was scheduled for St. Peter’s Square for Sunday morning. The pope died after suffering heart and kidney failure following two hospitalizations in as many months. Just hours earlier, the Vatican said he was in “very serious” condition but had responded to members of the papal household.