Crews managed to prevent the world's largest offshore oil rig from sinking farther into the sea on Monday, four days after explosions crippled its structure and killed 10, its Brazilian owners said. They said the 40-story platform belonging to Brazil's state oil giant Petrobras had stabilized by Monday evening after workers pumped enough water out of the submerged compartments. They are injecting nitrogen and compressed air in a bid to remove nearly 3,000 tons of water weighing down the rig. Even so, the platform was listing more than ever, at a 27-degree angle. In the last 24 hours it has sunk 1.3 feet (40 cm). The platform has sunk almost 15 feet (4.6 m) since the blasts.