The Lake and the Island
Lake Peigneur sits in Iberia Parish in the Cajun flatlands of south Louisiana, roughly twelve miles from the town of New Iberia. Before November 20, 1980, it was unremarkable by almost any measure: a shallow, oval freshwater lake about two miles across, nowhere deeper than ten feet, fed by the Delcambre Canal to the south. Herons worked its margins. Pleasure boats crossed it in minutes. It was the kind of lake you could wade across in places.
Rising out of its northeastern shore was Jefferson Island, one of five salt dome islands in southern Louisiana. These islands are not islands in the conventional sense. They are the exposed tops of underground salt columns, Jurassic-era deposits that have been pushing upward through the sediment for millions of years, lifting the land above the surrounding marshes. Jefferson Island rises about twenty feet above the lake. Its salt dome extends more than 50,000 feet underground at its base.
The island took its common name from Joseph Jefferson, a nineteenth-century American stage actor famous for his long-running portrayal of Rip Van Winkle. Jefferson bought the island in 1869 as a hunting and fishing preserve and built a Victorian manor house there that still stands. After his death, the property passed through several owners before John Lyle Bayless Jr. developed the grounds in the 1950s into Live Oak Gardens, a botanical park with a glass-enclosed conservatory and walking paths through Spanish moss and live oak canopy. By 1980 it was a working tourist attraction, open to visitors from across the region.
Beneath the island and the lake, the Diamond Crystal Salt Company had been mining since 1919. Sixty years of extraction had carved out a city underground: shafts descending to over 1,500 feet, tunnels roughly 100 feet wide and 80 feet tall running for miles under the salt dome, multiple working levels including an inactive third level that had been sealed years earlier. The mine was one of the most productive in the country. In 1980 it employed hundreds of workers and had a safety record that included winning the National Mine Rescue Championships three consecutive years running.
The Drill That Was in the Wrong Place
Texaco had won State Lease 124, a state-issued permit to explore for oil beneath the lake. The company subcontracted drilling operations to Wilson Brothers Corporation, which positioned a floating platform on the lake surface and began boring downward. Texaco's surveyors triangulated the drill site's coordinates against the shoreline. Diamond Crystal Salt Company had its own maps of the mine tunnels below.
The two sets of data did not agree. Exactly whose numbers were wrong has never been definitively settled. A subsequent investigation found the drill site was positioned hundreds of feet from where Texaco believed it to be, placing the bit directly above the inactive third level of the mine. Whether this was an error in Texaco's triangulation, a discrepancy in Diamond Crystal's maps, or some combination of both was never conclusively determined in court. What is certain is that no one on the drilling crew knew a mine existed below them, and no one at Diamond Crystal had informed Texaco of the mine's precise extent.
The drill went down. At approximately 1,228 feet, the 14-inch drill assembly became stuck. The crew spent two and a half hours attempting to free it. Then the platform began to tilt.
| Measurement | Before (Nov. 19, 1980) | After |
|---|---|---|
| Maximum depth | ~10 ft (3 m) | ~200 ft (60 m) |
| Water type | Freshwater | Saltwater |
| Area | ~4.5 km² | ~4.5 km² |
| Deepest lake in Louisiana? | No | Yes |
| Salt mine below | Active, 55 workers underground | Flooded, closed 1986 |
| Jefferson Island | 65+ acres of botanical garden intact | ~65 acres collapsed into lake |
The Breach
When the 14-inch drill bit finally punched through the roof of the inactive third level, it opened a small hole at the base of a ten-foot-deep lake sitting above a mine shaft that descended 1,300 feet. The physics took over immediately. Freshwater under gravitational pressure began pouring through the breach. Salt dissolves in water. The hole got bigger. The water moved faster. The hole got bigger still.
Within minutes, the breach had widened from a 14-inch perforation into something the lake could drain through. The drilling platform began to tilt as the lakebed shifted beneath it. The crew evacuated onto the shore. They watched the $5 million platform lean, then slide, then disappear. The lake had swallowed it whole.
A whirlpool opened on the lake surface, approximately 150 feet across and accelerating. It was not a gentle swirl. Witnesses described it as a roaring drain, pulling water in from every direction. The suction extended outward from the vortex, reaching barges moored in the Delcambre Canal where it feeds the lake from the south. Eleven barges, some laden with equipment for the drilling operation, were pulled one by one into the whirlpool and down into the mine. A tugboat followed. A dock went. Trees along the shore began falling into the water as the lakebed collapsed inward.
Fifty-Five Miners Underground
At the moment the drill broke through, fifty-five Diamond Crystal employees were working in the mine at various levels below the lake. Some were at 1,300 feet. Others were deeper still, at 1,500 feet. They were operating vehicles, running equipment, going about a normal Thursday morning shift.
The first warning came not from above but from the mine itself. Electrician Junius Gaddison, working at the 1,300-foot level, heard drums banging together and looked up to see a muddy stream more than two feet deep advancing toward his station. He understood immediately what it meant. He activated the mine's emergency signal: the lights flashed three times throughout the tunnels.
The Diamond Crystal crew knew what to do. They had drilled this exact scenario. The mine's safety program was not theoretical -- it had won national championships three years consecutively, and the workers had rehearsed evacuation procedures until the sequences were automatic. They abandoned their equipment and moved toward the elevator shaft. The elevator car held eight people. It ran continuously.
"When we got to the top of the thing, you could hear it. It sounded like you were in an ocean."
-- Myrna Romero, Diamond Crystal surveyor, on what she heard climbing toward the elevator
Myrna Romero, a surveyor working underground that morning, described taking the final cage to the surface while praying and reciting the Act of Contrition. The water was rising behind them as the elevator ran its last trip. Within the window of time the mine remained accessible, all fifty-five workers reached the surface. Not one person died. Six Diamond Crystal employees later received heroism awards for their roles in the evacuation.
The Island Collapses
Above ground, Jefferson Island was disappearing. The botanical garden's pathways ran along the lakeshore and extended across low-lying ground at the island's edge. As the lakebed collapsed inward under the pull of the draining water, the shoreline began moving. Trees fell. Ground that had been solid terra firma an hour earlier slid into the widening hole. Sixty-five acres of Live Oak Gardens, including a greenhouse, ornamental plantings decades in the making, and sections of the island itself, were swallowed.
The Joseph Jefferson House itself, set back from the shore on higher ground, survived. It still stands today. But the gardens that had made the island famous were gone, along with the lakebed on which they had partly sat. The hole that opened in Lake Peigneur's floor was not a sinkhole in the conventional sense. It was the mouth of an industrial cavity: miles of tunnels, vast chambers with 80-foot ceilings, an entire underground world now filling with water from above.
The River Runs Backward
The Delcambre Canal runs roughly fourteen miles from Lake Peigneur south to Vermilion Bay and the Gulf of Mexico beyond. Under normal conditions, it drains the lake. Water flows south. Shrimp boats from Delcambre use it to reach open water.
Within hours of the breach, the lake was emptying faster than a canal could drain it. The water level dropped so sharply that the flow reversed entirely. Salt water from Vermilion Bay began moving north through the canal toward the empty lakebed. The Gulf of Mexico was flowing into Louisiana.
Where the canal met the collapsed lakebed, it fell. The crater where the lake had been was now below the level of the canal's incoming water by more than 160 feet. A waterfall formed. It poured 164 feet down into the void, white and continuous, roaring in the Louisiana afternoon. It was the tallest waterfall in the state's recorded history, and it lasted several days until the lakebed refilled.
The nine barges that had been pulled into the mine during the draining came back up during the refilling. Air pockets trapped in the flooded tunnels gave way under pressure, and the barges surfaced like corks in the new saltwater lake. Two barges and the tugboat remained below. They have never been recovered.
The Salt Dome Below
To understand why the consequences were so extreme, it helps to understand the geology. Jefferson Island sits atop a diapir -- a body of relatively buoyant rock, in this case ancient halite, that has pushed upward through denser surrounding sediment over millions of years. The Gulf Coast of Louisiana and Texas has dozens of these formations. They are the reason the region has both its oil industry and its salt-mining industry: the rising salt dome pierces and displaces overlying rock layers, creating the structural traps where petroleum accumulates, and the salt itself is a valuable industrial commodity.
The Diamond Crystal operation had been carving out chambers in the Jefferson Island salt dome since 1919. By 1980, the mine included several working levels, with tunnels extending to depths of 1,500 feet and an inactive level that had been sealed years before the disaster. The total volume of the excavated space was enormous. When 3.5 billion gallons of lake water found its way in, the mine absorbed it and continued to dissolve. The salt walls of the chambers enlarged as the fresh water passed through them, widening the underground void and causing more surface land above to subside.
The mine closed permanently in December 1986. Since 1994, AGL Resources has operated the underlying salt dome as a pressurized natural gas storage and hub facility -- a common use for depleted salt caverns along the Gulf Coast, which offer ideal conditions for large-scale underground energy storage.
Settlement and Aftermath
Diamond Crystal Salt Company filed suit against Texaco almost immediately. The legal proceedings that followed took three years. In 1983, Texaco and drilling contractor Wilson Brothers paid $32 million to Diamond Crystal in an out-of-court settlement. Texaco, Wilson Brothers, and Diamond Crystal collectively paid an additional $12.8 million to the Live Oak Foundation to compensate for the destruction of the botanical gardens. The settlements were reached without any admission of liability by any party.
The investigation into the cause produced no definitive finding. Investigators concluded they could not determine whether Texaco had drilled in the wrong location, whether Diamond Crystal's mine maps were inaccurate, or whether both parties bore partial responsibility for the failure to communicate the mine's extent to the drilling crew. The exact distance between where Texaco believed the drill was positioned and where it actually was has never been officially established.
The botanical gardens were partially rebuilt in later years, and the Joseph Jefferson House reopened for tours. The wider Live Oak Gardens continued to operate as a tourist destination until 2001, when maintenance neglect and a subsequent hurricane combined to close it again. The current owners have pursued ongoing restoration. The house remains listed on the National Register of Historic Places.
The Lake Today
Lake Peigneur no longer exists in its original form. The ten-foot freshwater lake of 1980 is gone. In its place is the deepest lake in Louisiana, with a maximum depth of approximately 200 feet. Its water is no longer fresh. The salt water that poured in during the canal reversal mixed with whatever fresh water the lake eventually collected, and the chemistry of the lake shifted permanently. The surrounding ecosystem changed with it: the freshwater species that had populated the original lake were replaced by brackish-tolerant flora and fauna.
The underground chambers that swallowed 3.5 billion gallons in a single morning have since been repurposed. The salt dome that nearly destroyed the island above it now stores pressurized natural gas for distribution across the region. The mine shafts that the Diamond Crystal workers evacuated are flooded. The eleven barges -- nine of which resurfaced and two of which did not -- are down there somewhere in the dark.
The disaster produced no official death toll for humans, a fact that remains remarkable given the scale of what happened. The evacuation worked because the mine crew had practiced it. The proximity of working tunnels to a ten-foot lake happened because no one in the chain of communication between Texaco and Diamond Crystal had ensured the drill was positioned safely away from the mine's extent. A 14-inch hole at 1,228 feet was all it took to empty a lake, reverse a river, and swallow sixty-five acres of Louisiana.