The US could default on its debt as early as June 1st, if the debt limit isn't raised or suspended. That's the new and serious warning from Treasury Secretary Janet Yellen. Plus, at least six people are dead after a 70-vehicle pileup on an Illinois highway due to low visibility from a dust storm. And, production will be delayed on some of your favorite television shows after Hollywood’s writers are go on strike for the first time in 15-years.Also this morning: the Surgeon General has a plan to tackle America's epidemic of loneliness and isolation - his six-pillar approach to build our social connections. And, Tennis superstar Serena Williams is pregnant with baby number two, revealing the news during last night's Met Gala.To learn more about how CNN protects listener privacy, visit cnn.com/privacy