Is there any hope for Mariupol to resist against Russia?

Russia’s military says it controls almost all of Mariupol, while Ukraine’s Azov Battalion is still holding out in Azovstal, a huge steelworks overlooking the Azov Sea. Moscow issued an ultimatum (with the deadline set for yesterday, I might add), but Ukraine replied it wil fight to the end. Humanitarian corridors still have not been opened. If Russia captures Mariupol, it’ll control a vast swathe of southern and eastern Ukraine.