On 2 August 1981, the cargo ship "Primrose," carrying cargo between Australia and Bangladesh, ran aground in rough seas just off North Sentinel Island, stranding a small crew. After a few days, the captain dispatched a distress call asking for a drop of firearms and reported boats being prepared by more than 50 armed islanders intending to invade the ship. Strong waves prevented the Sentinelese canoes from reaching the ship and deflected their arrows. Nearly a week later, the crew were evacuated by a civilian helicopter contracted to the Oil and Natural Gas Corporation (ONGC) with support from Indian Naval forces.