September 24, 1909
At 4:20 a.m., an off-duty worker at the Fergus Falls City Light Station woke up and realized that the lights outside his window were much dimmer than normal — and getting dimmer. As the fog of sleep cleared his mind, he realized something was seriously wrong. He quickly got dressed, grabbed the on-duty supervisor, and they hurried out of the powerhouse and up the embankment just as the building dropped into the Otter Tail River. The constant loud rumbling made them look back in disbelief. The 10-ton dam was crumbling, and the water it held back was rushing through, breaking even more of the dam apart.
The two men ran to a nearby farm and alerted the family that lived there that a flood of water would soon descend upon them. The farmer saddled three horses, and the men set out to warn as many people as possible about the impending flood. Fergus Falls Electrical Superintendant met them on the road as he headed out to see why the electricity in town was off. He joined the group in alerting people in Fergus Falls.
By 6:30 a.m., the worst of the disaster had passed. Raging water from the collapse washed out four other dams along the river. The Red River Milling Company suffered $10,000 in damages, and many other mills were a total loss. The water had flooded many homes and businesses in and around Fergus Falls. Still, there were no reports of death or severe injury.
The Dayton Hollow Dam was more than 10 miles downstream. Its owners, Otter Tail Power Company, received enough warning to reach the dam by 6:15 a.m. and open the spillway, allowing the water to flow through unimpeded. Although it suffered minor damage, Dayton Hollow was the first dam downstream from the accident that wasn’t destroyed.
Because the Fergus Falls City Light Station provided power for the local electric grid, much of the area was at a stand-still until new power lines could be established and strung from another dam. Otter Tail Power Company’s dam at Dayton Hollow was the closest, so they were asked by the city to complete the work quickly so life could return to normal.
What Went Wrong
In the days following the disaster, gossip circulated about what caused the Fergus Falls City Light Station disaster. Everything from sabotage to the use of shoddy construction materials was discussed by locals.
Investigators studied the area for clues as to what brought the dam down. It turns out that when the dam was built in 1908, no one bothered to do a proper site evaluation. The dam was constructed on top of a group of natural underwater springs. The rough underwater current around the springs began washing away the concrete beneath the surface. The weakened concrete and pressure from the water behind the dam caused the structure to crumble.
Visit The Park
Broken Down Dam Park is located east of Fergus Falls. A sign at the trailhead directs visitors to a path to the dam ruins. The trail to the dam is easy with a small section of steep stairs. Several more steep stairs will take you down to the river.