Some analysts predict that the closure of Spirit Airlines will push other airlines’ fares up. | Giorgio Vera/AFP via Getty Images This story appeared in Today, Explained, a daily newsletter that helps you understand the most compelling news and stories of the day. Subscribe here. Anyone booking on Spirit Airlines kind of knew they were taking their flight into their own hands. America’s original ultra-low-cost airline has been on death’s door since the pandemic.  First, it tried to merge with