Tunnelling Companies in the Great War

Seems like related to the fact, that Russians are supposedly attempting to tunnel their way to Avdiivka instead of taking it by storm

https://www.pravda.com.ua/eng/news/2023/10/21/7425142/

There were some really crazy versions of this in the Dolomites. They would load up tunnels they drilled under the enemy's location in the mountain with massive amounts of explosives and boom.