[House Atreides]

The Russians, to a near certainty, have the detailed plans for all the underground structures.

[pierrem15]

If that were the case, they could have shut off ventilation. They haven't, so I doubt they have them.

Why do you guys seem to have belief in Russian infallibility after all their manifest failures?

[Petrosius]

The Russians, to a near certainty, have the detailed plans for all the underground structures.

I am sure that the Soviets had plans for the tunnels. Unfortunately for the Russians, most likely they were probably kept in a local office in Mariupol which, like the old Soviet nukes in Ukraine, would have fallen to the Ukrainians upon their independence.