If it were not for two Associated Press journalists in the besieged city of Mariupol, the world might not have learned what has been happening there as immediately as we have — nor in such irrefutable, horrifying detail.

For three weeks, Mstyslav Chernov and Evgeniy Maloletka have documented the destruction of the southern seaport by Russian forces who have encircled the city and trapped its people there. They’ve reported on mass graves filling with the bodies of children, the desperate measures the hungry populace is turning to and the destruction of a maternity hospital.