In recent days a neighbor and her dog were walking on Lake Mendota and fell through the ice at the pressure crack at the mouth of Spring Harbor where it meets the lake. Luckily a fisherman nearby heard a cry for help and rescued the woman. The dog was able to get out of the water on its own. Both are doing okay.
The mouth of the harbor is a known area of unstable ice. And there are many areas around the lake where the ice is unsafe. Snow cover and recent cold temperatures may make you think the ice is safe to walk on—use caution at all times in all areas.
Here is some safety information to help you prepare to go out onto lake ice.
https://dnr.wisconsin.gov/newsroom/release/64736
https://uwpd.wisc.edu/services/lake-rescue-safety/