DALLAS (AP) – Southwest Airlines says it won’t allow health waivers to its face-mask rule. Only children under 2 will be exempt from the requirement to cover their mouth and nose during flights. Meanwhile, Delta Air Lines says it will expand its coronavirus testing of employees to include at-home tests. Air travel has collapsed because of the virus pandemic, and airlines are trying to convince passengers and their own employees about safety. All airlines require passengers to wear masks during flights, and most extend the rule to airports too. But some people have complained about violators refusing to keep their mask on.