Who Is Responsible For Providing Sub Contractor's Staff Death Insurance Claim

Hi, My father is a sub contractor of a reputed mining company (contractor) where he is responsible for mantaining crusher plant. There are around 30-40 people under his company payroll working at the site. Recently one of our staff died in what they call "accident" where our contractor (company whose sc we are)'s staff had crushed our staff by payloader machine. since the man eho was operating mahine was not our staff but staff of our contractor it's not our fault. Now deceased family is asking for money and company is putting all the responsibility on us for giving claim compensation to the victim 's family. They are mentioning a clause in work order which says we are responsible for getting all kinds of insurance done including man power machine etc and providing the proof at their ho after signing we never did and they never bothered. how practical is this for a sc whose monthly billing amount is 3-4 lakhs...out of which he takes hone merey 20-40 thousand. Se signrd work order and now under pressure.