June 26, 1954 Tsunami: Michigan City, IN (Lake Michigan), United States

The event is referred to as the Great Chicago Seiche. The event began about 8:30 to 9:15 am, local time. Eight people drowned. A seiche across Lake Michigan struck 25 miles of Chicago's Lake Michigan shoreline, and effects were felt from Whiting, Indiana, to Waukegen, Illinois.

Prior to the event, a squall with winds up to 35 mph had been in the area. The New York Times (Reference #1850): "The seiche was believed to have developed as a result of the squall, and the sudden rise in atmospheric pressure that occurred about the same time." A Chicago Tribune article (Reference #2900), recounting the event, gave the same explanation. It took about 25 to 30 hours before the lake water regained its equilibrium.

Forecasters assembled reports from the Coast Guard and other sources said water had piled up water near Michigan City when a swell six to eight feet high was observed. "This evidently was the origin of the phenomenon. A drop in the wind allowed the wave to roll back across the lake, reversing the path of the squall." Lockridge et al. (Reference #541) commented that an underwater landslide might also have occurred, but give no source for this explanation. A landslide origin is highly unlikely.

The Great Lakes have a long-recorded history of destructive tsunami-like waves caused by convective storms (Anderson et al. 2015; Bechle et al. 2015, 2016). The most catastrophic event in Lake Michigan occurred on 26 June 1954, when seven people were killed (Ewing et al. 1954; Platzman 1965). (reference #12544)

Damages and flooding of coastal structures; eight people killed. In the morning of 26 June 1954, the water level of Lake Michigan rose by about 2–3 m within minutes along the fishing piers in Chicago, submerging the lakefront and tragically killing eight people (Bechle & Wu, 2014; W. M. Ewing et al., 1954). (reference #14271)