MEXICO CITY The cardinal said Mass in a shuttered cathedral. Soccer teams played to empty stadiums. A televised variety show filled its seats with cardboard cutouts. Mexico's overcrowded capital locked itself indoors Sunday, terrified by a new strain of swine flu that was spreading around the world. Mexico City residents chilangos, they're called are accustomed to living in public view. They eat greasy tacos at stands along smog-choked avenues, play pickup soccer games on potholed streets and snuggle with sweethearts on benches in tree-lined parks. But on Sunday even the enormous Zocalo plaza, where throngs of families congregate for street performances and open-air concerts, was all but empty. A handful of women wearing surgical masks knelt on the plaza's stones and prayed, their arms reaching upward in a lonely vigil. Soldiers in surgical masks shooed away the faithful at the cathedral, pointing to a board with pieces of paper. "There are no baptisms," one read. "No confirmations," read another. "No Masses," said a third. Inside, Cardinal Norberto Rivera delivered a sermon to nearly empty pews, his pleas for divine intervention relayed over television and radio. "Grant us the prudence and serenity to act with responsibility and to avoid being infected or to infect others," he appealed to the Virgin of Guadalupe, Mexico's patron saint. "Give help to health workers, keep vigil for the recovery of the sick and console those in mourning." For the first time in 300 years, the cathedral also removed from storage an icon of the Lord of Health, which was placed on the principal altar by a procession of worshippers, Mexico's government news agency Notimex reported. The Rev. Cuauhtemoc Islas said the icon would remain on the Altar of Forgiveness until the medical emergency is over. To the south of the city, the Pumas soccer team took on the Chivas at the picturesque Olympic Stadium, decorated by muralist Diego Rivera, but its sold-out volcanic-rock bleachers were empty. They tied 1-1 as fans followed from home on television. The television variety show "Make Me Laugh" filled its seats with cardboard cutouts bearing broad smiles on their faces. Somehow the jokes were still greeted with laughter and applause. The streets were largely deserted. The city canceled its weekly cycling day, in which major boulevards are closed to cars. The city's two main chains of movie theaters both announced they were closing temporarily. Restaurants and bars were empty. "We normally get 200 diners over the course of the day," said waiter Eduardo Garcia, wearing a surgical mask as he presided over empty tables of an Italianni's restaurant in the Zona Rosa neighborhood. "Today's pretty bad. Nobody's coming out of their houses." Schools have been canceled in the capital and the states of Mexico and San Luis Potosi until May 6. Hundreds of public events including concerts and sports matches have been called off to keep people spreading the virus in crowds. Zoos were closed and visits to juvenile correction centers were suspended. Twenty people have been sickened in the United States and six in Canada, and suspected cases were being reported as far away as Israel and New Zealand. The U.S. declared a public health emergency, providing for easier access to flu tests and medications, and enhanced surveillance along the U.S.-Mexico border. Mexico's health secretary reported the number of suspected swine flu cases had climbed to 1,614 late Sunday, including 103 deaths. Only 22 deaths have been confirmed. Most of those who died sought medical help only after the disease was well advanced, Mexico City Health Secretary Armando Ahued said. By Sunday, throngs of Mexicans were rushing to hospitals, some with just a fever. "We don't know if it's the flu or not, but we're very worried," said Sergio Zunun, a 59-year-old merchant, waiting outside the Obregon Hospital for his brother, a police officer, who complained of a respiratory infection. Others complained they had symptoms but couldn't find a doctor to see them. Jose Isaac Cepeda, who has had fever, diarrhea and joint pains since Friday, said he was turned away from two hospitals the first because he isn't registered in the public health system, and the second "because they say they're too busy." "No one anywhere is helping us," lamented his wife, Maria del Mar Perez. "What can we do? We don't have insurance. We don't have money to go to a private hospital." And while most people stayed home, others had no choice. Daniela Briseno, 31, swept a gutter with a broom made of twigs, wearing a jumpsuit and two dirty blue surgical masks she says she found. "I should be at home," she said, "but I have a family to support."