After finishing her shift, Katherina Faustino waits for other intensive-care nurses at the Nevada hospital where they work. They don’t leave immediately. “We go to the chapel,” she said. “We pray.” Ms. Faustino has been shaken by the sheer number of Covid-19 deaths she has witnessed in recent months as Dignity Health-St. Rose Dominican, Siena Campus faced a flood of patients that filled its ICU beds for weeks. “If you weren’t religious, you probably are now,” she said.