Nature displayed its power on the lake in July 1957, when a tornado several kilometres long and wide blew up along the water, lifting roofs off nearby houses and felling fences, telegraph poles, power lines and several hectares of forest. The fierce storm lasted around ten minutes, forcing people to hide in cellars and dugouts. Drivers tried to get out of forests to open spaces, but many vehicles suffered damage from falling trees and branches raining down. Cornfields were flattened, and the storm shaved the wooded Saimaa islands bare.
Human losses also occurred. When the storm started, a party of four had been fishing on the lake, and three of them drowned. The only one saved swam to shore through the furiously roaring waves. Another boat was thrown by the wind onto dry land, and the father and son occupying it were saved by hanging onto the sides of the boat for dear life. On a nearby campsite, dozens of tents flew away with the wind. One woman had been wheeling her bike along when the raging storm tore it from her hands. The woman hung on to a telegraph pole. Her face and hands were battered and scratched by hailstones and flying gravel.