'20 Days in Mariupol' Offers Unflinching Look At Horrors Of War In Ukraine

Documentary captures devastating destruction and suffering in besieged Ukrainian city of Mariupol.
Film chronicles efforts of Associated Press journalists to report on war and escape city.
Raw footage provides visceral account of Russia's assault and war's impact on civilians.
Harrowing scenes show relentless shelling, bombing of homes, hospitals and infrastructure.
Documentary provides vital on-the-ground perspective on brutality of war.