With former Pres. Barack Obama and former first lady Michelle Obama expected to take center stage on day two of the DNC and make their case for their longtime-friend, Vice Pres. Kamala Harris, Mary Bruce reports from the convention in Chicago, and Rachel Scott reports on former Pres. Donald Trump's counterprogramming in the battleground state of Michigan; James Longman reports on the chilling video that shows the moment a superyacht rapidly sunk off the coast of Sicily with 22 passengers aboard, including two Americans who are still unaccounted for; Trevor Ault has details on the FAA ordering new safety inspections for pilot seats on Boeing 787 jets after a string of concerning incidents; and more on tonight's broadcast of World News Tonight with David Muir.