Pope Francis visits heart of Mexico's ruthless drug-trafficking country

(AP)

Nuns, from Queretaro, stroll through the Zocalo, or central square, on the eve of Pope Francis' arrival, in Morelia, Michoacan state, Mexico, Monday, Feb. 15, 2016. On his one-day trip to the capital of troubled Michoacan state, the Pope will visit the cathedral next to the Zocalo, meet with youth, and celebrate a Mass with priests and seminarians, and religious men and women.(AP Photo/Rebecca Blackwell)

Workers prepare Morelia's cathedral on the eve of Pope Francis' arrival, in the Mexican state of Michoacan, Monday, Feb. 15, 2016. On his one-day trip to the capital Morelia, Francis will meet with youth and celebrate Mass with priests and seminarians, and religious men and women. (AP Photo/Rebecca Blackwell)

MORELIA, MEXICO - FEBRUARY 15: A seller with products of Pope Francis shouts at the downtown of Morelia on February 15, 2016 in Morelia, Mexico. On Tuesday, Pope Francis will travel to Michoacan State (Photo by Hector Vivas/LatinContent/Getty Images) (2016 LatinContent)

Maritza Parra Cortez watches preparations for Pope Francis' arrival from the upstairs balcony of her restaurant, La Imperial, located across the street from the cathedral in Morelia, Michoacan state, Mexico, Monday, Feb. 15, 2016. On his one-day trip Tuesday to the capital of troubled Michoacan state, the Pope will visit the cathedral, meet with youth, and celebrate Mass with priests and seminarians, and religious men and women.(AP Photo/Rebecca Blackwell)

Pilgrims, including a group of women from Mexico City who planned to spend the night outside the cathedral, fill the cafes and streets of central Morelia, on the eve of Pope Francis' arrival, in Michoacan state, Mexico, Monday, Feb. 15, 2016. On his one-day trip to the capital of troubled Michoacan state, the Pope will visit the cathedral, meet with youth, and celebrate Mass with priests and seminarians, and religious men and women.(AP Photo/Rebecca Blackwell)

Pilgrims from Bolivia, and the Mexican state of Aguascalientes, camp out in front of the cathedral on the eve of Pope Francis' arrival, in Morelia, Michoacan state, Mexico, Monday, Feb. 15, 2016. On his one-day trip to the capital of troubled Michoacan state, the Pope will meet with youth and celebrate Mass with priests and seminarians, and religious men and women. (AP Photo/Rebecca Blackwell)

A marching band of nuns, from Monterrey, play their instruments as they spontaneously parade through the streets of Morelia, on the eve of Pope Francis' arrival, in the Mexican state of Michoacan, Monday, Feb. 15, 2016. On his one-day trip to the capital Morelia, Francis will visit the cathedral, meet with youth, and celebrate Mass with priests and seminarians, and religious men and women. (AP Photo/Rebecca Blackwell)

A marching band of nuns, from Monterrey, play their instruments as they spontaneously parade on the eve of Pope Francis' arrival, in Morelia, in the Mexican state of Michoacan, Monday, Feb. 15, 2016. On his one-day trip to the capital Morelia, Francis will visit the cathedral, meet with youth, and celebrate Mass with priests and seminarians, and religious men and women. (AP Photo/Rebecca Blackwell)

Nuns file into Venustiano Carranza stadium for a Mass with Pope Francis, in Morelia, Mexico, Tuesday, Feb. 16, 2016. On his one-day trip to the capital of troubled Michoacan state, the Pope will also meet with youth and pay a visit the Morelia cathedral. (AP Photo/Rebecca Blackwell)

Nuns sing as they wait before dawn to enter Venustiano Carranza stadium for a Mass with Pope Francis, in Morelia, Mexico, Tuesday, Feb. 16, 2016. On his one-day trip to the capital of troubled Michoacan state, the Pope will also meet with youth and pay a visit the Morelia cathedral. (AP Photo/Rebecca Blackwell)