Pope Francis suffered a "respiratory crisis" during treatment for pneumonia, the Vatican said.
CHICAGO (WLS) -- Chicago faith leaders and the local Catholic community offered well wishes for Pope Francis Saturday after the Vatican said he suffered a "respiratory crisis."
The pope's condition remains critical, according to a statement from the Vatican.
The 88-year-old has been in the hospital receiving treatment pneumonia and a lung infection.
The Vatican said Pope Francis is alert, but continues to struggle when breathing on his own.
READ MORE | Pope Francis in critical condition after suffering 'asthmatic respiratory crisis,' Vatican says
Chicago-area worshippers were praying for his recovery Saturday evening.
In the pews of Holy Name Cathedral, words of prayer and song rang out, but with deeper meaning at Saturday night's mass.
"Hopefully, our prayers will get to him," mass attendee Peggie O'Neill said. "He's human, just like all the rest of us, and we just have to hope and pray that his condition will get better."
Pope Francis received blood transfusions Saturday to treat anemia after being in the hospital for more than a week with bronchitis and pneumonia.
The Argentina native is vulnerable to respiratory infections. As a young man, he suffered severe pneumonia that led to part of his lung being removed.
Cardinal Blase Cupich, Archbishop of Chicago, shared the following statement Saturday:
"We have received word that the Pope's condition worsened this morning. Please continue your prayers for his recovery and for the health care professionals working to lead him through this setback. We ask our Merciful Lord to restore Pope Francis to good health and to keep him free from pain as he receives treatment."
"He's got a lot of people rooting for him, and hoping for the best for him, and just making sure that he knows he has the support from people all over the world," mass attendee Mark Burgess said.
The pontiff is expected to remain in the hospital for at least all of next week.
"I remember when he said in the beginning, he said, 'Who am I to judge?' And that tells the whole story about the pope; really good person," mass attendee John Keeting said.
The Vatican said Francis will not deliver his weekly prayer this Sunday, missing the tradition for the third time in almost 12 years.
ABC News contributed to this report.