Bengaluru: Eight labourers, most of them from Bihar, were killed and several others injured after a massive rock collapsed on them at a stone quarry near Madapattana on the outskirts of Bengaluru on Thursday.Preliminary reports indicated that the boulder gave way due to loose soil, although it was not immediately clear whether quarrying operations triggered the collapse.Prime Minister Narendra Modi expressed grief over the incident."Pained to hear about the loss of lives due to a mishap in a stone quarry in Bengaluru Urban district of Karnataka. I extend my deepest condolences to those who have lost their loved ones. Praying for the speedy recovery of the injured," he said.Chief Minister DK Shivakumar ordered an inquiry into the incident and sought a report on its causes, including whether any illegal quarrying activity was involved.The government will provide compensation to the families of the deceased, Shivakumar said, adding that the immediate priority is to ensure such incidents do not recur anywhere in the state."It is the duty of quarry owners to ensure the safety and security of workers engaged in quarry operations. The government will take appropriate action against quarries that violate regulations," he said in a post on X.Home Minister Priyank Kharge said the incident prima facie pointed to negligence and that officials from the Mines Department and the police were investigating the matter.Yeshwantpur MLA ST Somashekar demanded stringent action against the owner of the stone crushing unit and alleged a nexus involving officials from the Mines, Police and Forest departments.Bihar Minority Welfare Minister Mohd Zama Khan said the Bihar government was coordinating with the Karnataka government following the deaths of migrant workers from the state.