It's late summer, 1941, in Leningrad, the second largest city in the Soviet Union.

A school teacher named Maria hurries a group of young children through the streets.

Overhead German fire planes, swoop low, spewing machine gun fire.

Maria has the children stick close to the brick walls with the buildings lining the street,

desperately trying to find safety.

A month ago, Nazi Germany broke its non-aggression pact with the USSR

and attacked Russia with the biggest invasion force in the history of warfare.

Since then, German forces have advanced rapidly. Now Leningrad is under attack, and Maria is

risking her life to evacuate the children in her care before the Germans cut off all escape routes

from the city. The bomb lands at the other end of the street, and the children throw themselves to the ground.

Maria urges them back to their feet again.

They're too exposed to enemy fire out in the open.

Maria decides they must get to the train station, so they have to keep moving.

But as the children get up, another plane roars overhead.

Bullets shatter the windows in a nearby apartment block and the children scream.

But Maria can see the train station entrance now. It isn't far. Picking up one small child who's sobbing uncontrollably,

she hurries the others along the street as fast as she can. Finally, they run into the train station's cavernous lobby. It's packed with people also desperate to escape the city. Maria knows the children with her

are more protected here than out on the streets, but she also knows they won't truly be safe

until they've escaped Leningrad.

It will take several more weeks for the German forces to finally cut off the last safe route out of Leningrad.

But after that, there will be no escape.

Nearly three million people will be left trapped inside the city, and they'll remain

...