H.W. Grasse, was the Moorhead Weather Observer, working for the United States Weather Bureau for many years in the early part of the 1900s. One of his responsibilities besides making weather observations was to take river level samples and in the winter ice thickness readings. These measurements were taken at the bridge connecting Front Street in Fargo and Main Street in Moorhead when the river station was established in 1901.
On the morning on January 24, 1905, H.W. Grasse in his notes for the day wrote that the Observer (H.W. Grasse) hit an air pocket in the river and took a “ducking” into the water. Of note, the high and low for that day was -10° F and -20° F. Considering he was taking readings in the morning, the air temperature at the time was very likely much closer to the -20° reading than the -10° maximum. Not that a few degrees at those temperatures makes much of a difference as any temperatures at that level and plunging through the ice is life threatening. Fortunately, according to the newspaper account from the Moorhead Daily News (January 24, 1905) of the event (presented below), Mr. Grasse fell into a shallow area of the river and only a soaking occurred.
It is an example how ice is never perfectly safe and also some of the perils of being a weather (and river) observer. Thanks to Mark Peihl of the Historical and Cultural Society of Clay County for sending me the clipping from the paper that day.