The first signs of damage appear in the main corridor near the branch for the first casemate.
The continuous process of decay is especially evident in the pavement, raised near a longitudinal crack and pierced with holes, and the ceiling which also has gaps and loose blocks of concrete. You adventure into this area at your own risk.
At the branch of the second casemate the collapse of the arch has been total and you can't continue.

Ruptures in the pavement of the main entrance corridor after the branch of the first casemate (Photo by Ottavio Zetta - 09/10/1999).

This image taken looking toward the entrance shows a large loose concrete block at the beginning of the area before the branch for the second casemate (Photo by Ottavio Zetta - 09/10/1999).