India Today has most interesting reporting on this unfortunate incident.

According to India Today, Comptroller and Auditor General of India (CAG) report says “There was no evidence in the records made available to audit regarding the conduct of any scientific study or analysis prior to grounding the project”.

The geotechnical report, Tunnel Seismic Prediction was prepared in January 2020 by Amberg Tech AG. It indicates risks like a fault zone.

"Repeated contractor changes".

https://www.indiatoday.in/amp/india/telangana/story/poor-planning-contractor-change-cag-report-raised-telangana-tunnel-issue-2691697-2025-03-10