In South West Michigan, least ways in our area, ice thickness on local lakes has not been to the depths that ice divers associate with being thick enough for groups of divers to make a hole big enough to have an ice dive. For this type of group activity having a minimum of 5 inches of clear ice is desired but having 8 inches or so is better if your using snowmobiles to haul gear and provide emergency transport if necessary. But for ice fishing 4 inches of ice is considered safe.
With that said, it is not unusual for individuals, when making holes to fish or waiting around for the fish to bite, to occasionally drop items that seem to gravitate to the only opening in the ice on the entire lake. Items like cell phones.
So far this January, Kevin Ailes (Mud Club Member & Wreck Researcher) has been very busy attempting to recover such items with the majority of searches ending with success.