June 7th 1956
Jacob Schoellkopf built his second power plant directly in front of the original plant in 1895. The sides of the gorge were walled in but behind the walls, shafts carried water down the 210 feet to the turbines located just above the water level. Following these shafts and rear walls of the new plant were old cuts in the rock face which were used in the past. Over the years, water seeping behind the wall had undermined the rock face of the gorge behind the plant.
On the morning of June 7th 1956, workers noticed water seeping into the plant from the back wall. By mid afternoon, the cracks in the rear wall were widening while 40 men worked with sandbags to stop the flow of water.
At 5:00 p.m., the Schoellkopf Power Station sustained a catastrophic collapse which destroyed two-thirds (2/3) of the plant. Six generators capable of producing 322,500 horsepower had been demolished. Damage was estimated at $100 million dollars. The most devastating was the sudden loss of 400,000 kilowatts of power from the power grid. Suddenly a loud rumble was heard from behind the wall and the wall began to collapse. One of the workers died. Employee, Richard Draper of Lewiston was killed. The rest escaped unscathed. The entire southern portion of the plant collapsed into the river below. As the generators blew apart, some debris was propelled to the Canadian side of the gorge.