Archbishop Charles Chaput will celebrate Mass today in honor of Pope Benedict XVI at the Cathedral Basilica of Saints Peter and Paul.
Mass is scheduled to begin at 6:30 p.m. at the cathedral which is located at 18th Street and Benjamin Franklin Parkway.
Benedict spoke to tens of thousands of people in St. Peter's Square Sunday morning in one of his final addresses as head of the Catholic Church. He was the first pope in some six centuries to step down, according to Reuters.
On Wednesday, he will hold his last general audience in St. Peter's Square and on Thursday he will meet with cardinals and then fly to the papal summer retreat south of Rome, according to Reuters.
The papacy will become vacant at 2 p.m. EST on Thursday.
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Cardinals will begin meetings the next day to prepare for a conclave, likely to start in mid-March, where they will elect a new pope from among themselves.