Largest US Catholic church isn't big enough for papal Mass; 25,000 to attend outdoor service

Deacon David Cahoon, right, from the Archdiocese of Washington and professional carpenter, and head carpenter Carlos Hernandez, left, continue to work on the altar that Pope Francis will use during his Mass next week, inside the Basilica of the National Shrine of the Immaculate Conception in Washington, Thursday, Sept. 17, 2015. (AP Photo/Pablo Martinez Monsivais) (The Associated Press)

Workers hang Papal colored drapes over the main entrance to the Basilica of the National Shrine of the Immaculate Conception in Washington, Thursday, Sept. 17, 2015, in preparation for Pope Francis Mass next week. (AP Photo/Pablo Martinez Monsivais) (The Associated Press)

Secret Service Director Joseph Clancy, right, and other members of the Secret Service, arrive at the Basilica of the National Shrine of the Immaculate Conception in Washington, Thursday, Sept. 17, 2015 as preparation are being finalized for Pope Francis' mass next week. Secret Service provides security in the U.S. for visiting heads of state. (AP Photo/Pablo Martinez Monsivais) (The Associated Press)

The largest Catholic church in the Americas isn't nearly big enough to hold everyone who wants to see Pope Francis perform a Mass of canonization next week.

Instead, the pope will canonize Junipero Serra from a temporary sanctuary that's being built on the east portico of the Basilica of the National Shrine of the Immaculate Conception.

The church can comfortably seat 3,500 people, and up to 10,000 can cram inside on special occasions like Easter. But the pope's visit is more than that. The Archdiocese of Washington is distributing 25,000 tickets to the Mass next Wednesday.

Cardinal Donald Wuerl, the archbishop of Washington, says the Basilica is the ideal location for the first pope from the New World to canonize a friar who brought the first Catholic missions to California.