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In a recent interview on Newstalk 107.9, Jay Calderwood shared a harrowing first-hand account of the Teton Dam collapse as Idaho observes the 50th anniversary of the catastrophe. Calderwood, who was working as a general excavation foreman at the time, was one of the last people on top of the dam before it gave way on June 5, 1976.

Speaking with hosts Neal Larson and Julie Mason, Calderwood described arriving at the site after receiving reports of a leak. He operated a D9 bulldozer, attempting to push massive rocks into a growing whirlpool in a desperate bid to slow the breach. Despite the crew’s efforts, the structural integrity of the dam failed rapidly. Calderwood recalled the moment the general superintendent felt the ground tremble and signaled for an immediate evacuation.

The escape was a matter of seconds and inches. Calderwood described backing his bulldozer toward the south abutment while the ground in front of him began to fall away. “I thought, oh man, I’m not going to make it,” Calderwood said, noting that 20-foot sections of the dam were sloughing off as the gap widened. He told the program that he considered jumping from the machine but realized he could move faster by staying in the cab and backing up at full speed. He reached the safety of the canyon wall just moments before the section he had been occupied on vanished into the rushing water.

From his vantage point on the side of the river, Calderwood watched the floodwaters engulf a two-story powerhouse and a nearby concrete plant. He described the sight of the water moving down the canyon, mowing down large cottonwood trees “like a haymower.” While 11 people lost their lives in the subsequent flooding of Sugar City and Rexburg, Calderwood noted that the project engineer assured him at the time that downstream residents had been notified as soon as the leak was discovered.

In the months following the disaster, Calderwood led a crew to reconstruct the railroad grade that had been destroyed by the surge. Reflecting on the personal impact, he described the emotional reunion with his family in Victor, Idaho, who spent hours without any means of knowing if he had survived the collapse.

Marking the 50th anniversary of the catastrophic collapse of the Teton Dam, dam safety engineer Dr. Nathaniel Gee joined Newstalk 107.9’s Neal Larson and Julie Mason to discuss his new book, “Failure and Fortitude.” In the interview, Gee detailed how a combination of political pressure, unconventional engineering, and poor geology led to one of the most significant engineering failures in United States history.

Gee, who works for the Bureau of Reclamation—an agency whose modern safety programs were heavily influenced by the Teton disaster—highlighted the political maneuvering that fast-tracked the project. According to Gee, former Congressman Ralph Harding prioritized the dam’s authorization in 1964 as a political strategy. Despite warnings about the site’s fractured geology, the project moved forward. To keep the dam financially viable under emerging environmental regulations, engineers utilized an experimental “key trench” design that lacked traditional filtration layers. This decision ultimately allowed water to erode the dam’s core, leading to the breach on June 5, 1976.

The interview also touched on the human element of the tragedy. Gee recounted the harrowing experience of Daryl Griggs and David Benson, who were fishing downstream when the breach occurred. While Benson was the first fatality of the disaster, Griggs survived after being swept into a tree. Despite 25,000 people being displaced by the floodwaters, only 11 lives were lost. Gee attributed this relatively low death toll to the timing of the collapse on a clear Saturday afternoon and the rapid, informal communication networks within the local community.

Regarding the possibility of rebuilding, Gee stated that while modern engineering could safely construct a dam at the site today, the costs would be significant due to the foundation requirements. He emphasized that the subsequent recovery effort was a testament to regional resilience, noting that many residents were initially reluctant to file federal claims for their losses. Gee concluded that the disaster serves as a permanent reminder of the importance of both engineering rigor and community preparedness, noting that while infrastructure can fail, the strength of a community remains a primary defense during a crisis.