Six workers were killed when iron ore mining dumps collapsed in the Tollem mines in Goa, police said on Sunday.
The nearly 100-metre high mining dumps - covering an area in a 200-metre radius - gave way on Saturday and buried excavating machines and operators beneath them in the interior Sanguem iron-ore mining heartland of the state, some 60 km from Panaji.
The landslide was so sudden that those trapped were unable to even react, according to eyewitnesses.
Military personnel carried out rescue operations at the site.
Ironically, the disaster came on the eve of the Mines Safety Week, which has been "postponed due to unavoidable circumstances".
Police said a case of negligence was filed against the board of directors and managers of the mine.
Governor SC Jamir and Chief Minister Pratapsing Rane expressed shock over the incident.
Much of the mining activity in Goa is carried out in privately run and badly ravaged open cast mines tucked away in interiors, away from the coastal region that is a prime tourist destination.