The operation, carried out on Monday morning, is part of preliminary works for the rehabilitation of the property. The reopening allowed access to the subsoil and the unblocking of the shelter's entrance, which was believed to connect with the theater's facilities according to oral testimonies.

During the exploration, a tunnel approximately 15 meters long, excavated directly into the rock, was discovered. However, it was confirmed that the tunnel had no continuing galleries, corroborating the hypothesis that the shelter remained unfinished.

After analyzing the documentation obtained and information provided by the Fire Department, including images captured by a drone and advice from the Collapsed Structures Group (GREC), human access to the interior was discouraged, and the opening was subsequently sealed again.

These works are part of the preliminary actions for the waterproofing of the building and its surroundings, taking the opportunity to document and study this historical structure.