After nearly four days, a fire in a high speed diesel (HSD) storage tank at an offshore oil terminal has been finally put out and cooling operations started, a top official said here on Tuesday. There were no casualties in the fire which erupted following a lightning strike on Friday around 4.30 p.m. on the tiny Butcher Island, which serves as an oil terminal for the public-sector Bharat Petroleum Corp Ltd (BPCL) in the Arabian Sea off Mumbai harbour. "The last flame was seen around 10.50 p.m. on Monday night and after that the cooling operations have been undertaken."The loss of the HSD will be ascertained shortly. Our priority was to fight the blaze without casualties while ensuring it did not spread, which we achieved," BPCL Executive Director Manohar Rao told IANS. According to official sources earlier, the capacity of the affected tank was said to be around 40,000 tonnes, which was nearly 25 per cent filled with HSD at the time the fire broke out. All of the stock stored has reportedly been lost in the flames, though Rao declined to quantify the loss. Located around 8.3 kilometres from Gateway of India, the small island, also known as Jawahar Dweep, belongs to the Mumbai Port Trust and serves to offload crude oil from oil tankers which is stored in the containers there before being transferred via pipelines to an oil refinery in Wadala. Apprehensions have been raised over the possible ecological fallout of the conflagration with unconfirmed reports of black rains as the smoke billowed high into the atmosphere, soot spreading over a large area due to winds and descending over the sea-water, affecting marine life in the area.