Uttarakhand tunnel collapse: How workers were rescued after 17 days

All 41 workers trapped inside the Silkyara tunnel in Uttarakhand since November 12, were successfully rescued late Tuesday. The initial plan under the multiple-agency led rescue operation was to evacuate workers through horizontal drilling with the expertise of international tunnelling experts. However, in the final stretch of the operation, the banned manual “rat-hole”-mining technique was employed after high-tech machines, or augers, failed to drill through the nearly 60 metres of rock that has threatened to bury the workers.

The workers were pulled out through a passageway made of welded pipes which rescuers previously pushed through rocks.