On August 4, 2018, at approximately 5:05PM, the Lake County Sheriff’s Marine Unit was dispatched to the Petite Lake Sandbar (located on the Chain O’Lakes) for a report of an unresponsive person. When Marine Unit Deputies arrived, the 23-year-old, of Arlington Heights, had already been pulled from the water. Marine Unit Deputies arrived quickly, performed CPR on the man, and deployed an Automated External Defibrillator (AED) until paramedics arrived. The man was transported to Advocate Condell Medical Center in Libertyville, where he was subsequently pronounced deceased. Preliminary investigation shows the man did not know how to swim and went under the water where the depth was 8-10 feet. He was under the water for approximately two minutes before being pulled out. Alcohol may be a factor.The Lake County Coroner’s Office will conduct an autopsy on the man tomorrow.