$40,047,425,768,420 in U.S. Debt, and an Experimental Vaccine for Skin Cancer

Plus, could tweaking flight paths reduce global warming? Here’s what we’re covering: U.S. Debt Hits $40 Trillion as America’s Borrowing Binge Continues, by Alan Rappeport Israel Opens Criminal Inquiries Into Killings of Hind Rajab, 5, and of Medics, by Isabel Kershner A New mRNA Vaccine Could Prevent Skin Cancer From Returning, by Carolyn Y. Johnson U.K.