Several people are feared dead in a major fire today that destroyed a big oil platform off Mumbai coast, disrupting crude production from the country's prime oil field.The ONGC platform, located about 160 kms from the coast, had up to 300 people on board when the accident, apparently caused due to collision of a vessel docked nearby in high tide, took place at 1630 hours, reports reaching here said."We had a major fire and the platform has been completely destroyed. There is bound to be some loss of life and injuries," petroleum minister Mani Shankar Aiyar said at a hurriedly called press conference here but declined to hazard a guess on the number of casualties.Navy and Coast guards were immediately pressed into rescue operations, and about 160 persons were evacuated to safety within hours as the fire died because the platform collapsed. Search and rescue operations will continue through the night.ONGC chairman and managing director Subir Raha said the platform, which gathered oil from up to 20 wells and supplied 80,000 barrels per day, would take several months to return to normal production.Prime Minister Manmohan Singh, who is scheduled to make an aerial survey of the flood affected areas of Mumbai and other parts of Maharashtra, is taking Aiyar along with him for a first hand assessment of the damage tomorrow.This is the second major fire in four years at the Mumbai High fields.