On the morning of November 21, 1980, a Texaco oil rig team on Louisiana's Lake Peigneur noticed that their drill had seized up below the surface of the shallow lake. The twelve men were baffled when they couldn't free the drill. Then, following a series of loud pops, their platform begin to tilt toward the water. Alarmed, the men scrambled to the shore. They had no idea that they had just redrawn the landscape of Iberia Parish. They had managed to permanently transform a 10-foot-deep freshwater lake into a 200-foot-deep saltwater one.

A shorter-than-usual day in the salt mines.

An hour and a half later, the men watched their $5 million, 150-foot-high derrick somehow vanish into a lake that had an average depth of less than three feet. It seems their drill had accidentally penetrated a main shaft of the Diamond Crystal salt mine, whose tunnels crisscrossed the rock under the lake. Lake water was now rushing into the mine through the rapidly expanding 14-inch hole in the salt dome, with a force ten times that of a fire hydrant. Fifty miners were racing the rising waters, using mine carts and an agonizingly slow elevator to exit the mine eight at a time.

That "oops" face when you turn a nice lake into a cauldron of death.

Amazingly, the miners all escaped, but the drama was just beginning for Lake Peigneur. The oilmen watched in shock as the water began to circle around its new "drain," making the lake into a swirling vortex of mud, trees, and barges, the largest man-made whirlpool in history. A tugboat, a dock, another drilling platform, a parking lot, and a big chunk of nearby Jefferson Island got sucked into the abyss.

For a few days, Iberia Parish gets the whole Book of Revelation.

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Lake Peigneur used to drain into Vermilion Bay via the Delcambre Canal, but once the lake had emptied into the mine, the canal changed direction and salt water from the Gulf of Mexico flooded into the muddy lake bed. (To this day, Lake Peigneur has a brackish ecosystem very different from the way it was in 1980.) The backwards flow created a temporary 164-foot waterfall, the tallest in the state, and 400-foot geysers burst periodically from the depths as compressed air was forced out of the flooded mine shafts.

Texaco learns to double-check its math.

The drilling companies eventually agreed to pay $45 million to the owners of the mine and other flooded local businesses. Why were they digging for oil directly above an active salt mine? you might ask. Didn't they know? They did! The Texaco platform was drilling in the wrong place because of a mapping mistake: an engineer mistook transverse Mercator projection coordinates for UTM coordinates. See, I've been trying to tell you guys, this is why geography matters!

Explore the world's oddities every week with Ken Jennings, and check out his book Maphead for more geography trivia.