Cowering in the labyrinth of Soviet-era bunkers far beneath the vast Azovstal steelworks, Natalia Usmanova felt her heart would stop as Russian bombs rained down on Mariupol, sprinkling her with concrete dust.
Usmanova, 37, spoke on Sunday after being evacuated from the plant, a sprawling complex founded under Joseph Stalin and designed with a subterranean network of bunkers and tunnels to withstand attack.
