When Titans inexplicably begin to invade the southwestern territory of Wall Rose, Nanaba notes that if Krolva District to the west or Trost District to the south were breached, they would have received a warning before the Titans reached them. Due to this, she and Mike Zacharias conclude that an area of the Wall itself must have been breached.
During the exploration to find the breach in Wall Rose, Captain Hannes says that after spending all night looking for a hole between Krolva District and Trost District, the Garrison unit found nothing and did not run into any Titans either.
- In the original version of Chapter 35, Nanaba refers to Krolva as "Nedlay" (ネドレイ Nedorei?). However, in Volume 9, the name was changed to "Krolva."