Search efforts began Monday evening after a man plunged into Lake Michigan while walking on shelf ice, according to law enforcement.
At approximately 5:30 p.m., five people were walking on shelf ice at Indiana Dunes National Park's West Beach when waves began crashing against the ice, and cracking occurred, according to Officer Nicole Baumann with the Indiana Department of Natural Resources. One of the individuals then fell in.
Others in the group tried to rescue the victim, a 22-year-old man from northwest Indiana, but the large waves and unstable ice hindered their efforts, authorities said.
A helicopter with the Lake County Sheriff's Department was searching the waters for any signs of the individual late Monday. Conditions were deemed too dangerous for divers to enter the water, authorities said.
One day earlier, the Indiana DNR Law Enforcement posted on Facebook about the dangers of shelf ice along Lake Michigan's shoreline, explaining officers encountered multiple walking on the ice that day.
Due to the way shelf ice forms, it is full of air pockets and weak spots, the DNR explained. As the temperatures begin to climb, the shelf ice will only get more dangerous.