Officials in the Upper Midwest are warning residents of the dangers of venturing out onto frozen lakes and ponds after several people fell through the thin ice, leaving at least one person dead.

Police in the town of Woodbury, Minn.,, said two people, including a teenage boy, needed to be rescued after falling through thin ice on Markgrafs Lake on Monday.

Police said in a Facebook post that they received a report that someone had fallen through the ice around 4:30 p.m. local time, and when officials arrived at the scene, they were told a second person who had gone out onto the ice to help the first victim had also fallen in.

First responders were able to pull that person from the water, but the second person, who was identified as a teenage boy, had gone under the water and ice before they arrived and was not able to be immediately rescued.

Divers eventually located him and both victims were taken to a local hospital. Their conditions were not known as of Tuesday morning.

Police said another water rescue had taken place earlier in the day when a 

To the north, police said the body of an ice skater from Duluth, Minnesota, was pulled from Woodstock Bay in Superior, Wisconsin, after he fell through the ice on Sunday night.

Police in Douglas County, Wisconsin, said 78-year-old Gregory Garmer left his home around 1:30 p.m. Sunday to go ice skating and never returned.

A search was launched, and police said his body was eventually located around 4 p.m. Monday.

There is no reliable “inch thickness” to determine whether the ice is safe, and ice-covered snow should always be considered unsafe.

Anyone venturing onto the ice should take proper precautions, such as using the proper tools and techniques to check ice conditions.

It’s always advised to use the buddy system and to let other people know your plans in case of an emergency.