The Fond du Lac County sheriff’s office says an incident on Lake Winnebago a few days ago illustrates how dangerous ice conditions still are. A truck went through the ice on the northern half of the lake…fortunately there were no injuries. Fond du Lac County sheriff’s sergeant Jeff Bonack says after last week’s deep freeze he wasn’t surprised that some people maybe thought the ice was thick enough. Bonack says he’s concerned that conditions won’t improve this week with temperatures forecast above freezing by Saturday.