conant, wasn't the kind of person given to fear or exaggeration.et -- >> my grandfather was really so terrified of a nuclear conflict, i think the idea that mutually assured destruction would have held for almost 70 years would have surprised him. >> reporter: in the late '30s dmoont was a brilliant chemist, a veteran of poison gas during world war i and a successful president of harvard university. but his life changed course after albert einstein warned the white house about the potential for extremely powerful bombs. that triggered a desperate race to build a nuclear weapon before hitler's germany. and the task of winning fell to conant a terms of the bomb's development. >> reporter: what happened in the summer of w weapon. a blast so shocking that conant from a nearby bunker was sure the team had miscalculated. >> and he thought in that moment the world is over? >> he did. terrifying. absolutely terrifying. >> reporter: just three weeks later, hiroshima. and then nagasaki. still, the only war-time use of a nuclear weapon. >> we have spent more

i don't know if there will be a guarantee for the democrats again in february. >> alex conant, see youhree weeks. and jaime gangel. thank you very much. we are also getting some breaking news from the pentagon. a russian spy ship has been spotted off the coast of north korea. what's going on? we'll find out. we danced in a german dance group. i wore lederhosen.man. when i first got on ancestry i was really surprised that i wasn't finding all of these germans in my tree. i decided to have my dna tested through ancestry dna. the big surprise was we're not german at all. 52% of my dna comes from scotland and ireland. so, i traded in my lederhosen for a kilt. ancestry has many paths to discovering your story. get started for free at ancestry.com. every day we hear from families who partnered with a senior living advisor from a place for mom to help find the perfect place for their mom or dad thank you so much for your assistance in helping us find a place. mom feels safe and comfortable and has met many wonderful residence and staffers. thank you for helping our family find our father a ne