today is marking a difficult milestone that changed our country and the world. tributes will be under way at all three sites where nearly 3,000 americans lost their lives. of course, president biden will visit them right here in new york city where the first two planes crashed into the twin towers of the world trade center.we a commemoration ceremony is set to begin around 8:40 a.m. eastern. the obamas and the clintons, they will also be attendance. former president trump says he will visit ground zero, too. though it is unclear if he will be at the actual ceremony. of course, later this morning, a ceremony at the pittsburgh. the site of the second terrorist attacks a big american flag, just moments from now, unfurling over the side of the building as the sun rises in our nation s capitol. we will take you there live as it happens. we ll take you to shanksville, pennsylvania, where the fourth plane, united flight 93 crashed before reaching washington, d.c., thanks to