suffering in ukraine, leaving to the fastest-growing refugee crisis since world war ii. and three weeks, nearly three and a half million people have fled. this is suffered the most acute anguish of this war, is the city of mariupol. it is 40 miles away from the russian border, and a place where the majority of people, the overwhelming majority, our russian speakers. in fact less than 1% of the people in the city, around 400, 000, speak ukrainian at home. the citizens of mariupol are the people who ve russian president vladimir, putin, claims to be protecting in his propaganda. he, and russian state media, justify the invasion by claiming that ukraine is carrying out to genocide against russian speakers in the eastern part of the country, like people who live in mariupol. yet, it is their, where we have seen putin s barbarous plans play out. listen to nbc news correspondent, for his report.