Mstyslav Chernov: Pulitzer prize winner on Mariupol atrocities

Mstyslav Chernov is part of a small team of Associated Press Ukrainian journalists who this week won a Pulitzer Prize for their fearless reporting from Mariupol last year. For nearly three weeks they were the only international journalists in the port city, exposing the horrors of the Russian siege including an airstrike on a children's hospital and maternity ward.