You should read the description of the accident:

“Over the next few days the resulting man-made sinkhole swallowed up the oil rig, 11 barges, a tugboat, 35 hectares of land and part of a house. A canal that drained the lake into the Gulf of Mexico began flowing backwards as the water level fell, briefly creating the tallest waterfall in Louisiana, while muddy geysers erupted from mine shafts. Somehow, all 50 people working in the mine managed to get out ahead of the rising floodwaters.”