Authorities recovered the body of an elderly northern Minnesota woman submerged in her car in Island Lake early Saturday, hours after family members reported her missing.

Darlene Lukovsky failed to return from a trip to the grocery store in Duluth, about 18 miles from her Fredenberg Township home, on Friday, according to the St. Louis County Sheriff’s Office. She was to turn 80 years old on Sunday.

Lukovsky told relatives that she was leaving the supermarket about 1:30 p.m. Friday. They called 911 when she failed to return.

Sheriff’s deputies and rescue volunteers began tracking the likely routes Lukovsky would have traveled home. Officers realized it was foggy during her drive and thought she may have lost her way.

A 12-hour search eventually led authorities to Lukovsky’s Honda CR-V just off Bear Island Road. Her body was removed from the water.

“It appears Darlene missed a curve in the road, possibly due to the foggy conditions, and drove into the water,” according to the Sheriff’s Office. The vehicle will be pulled from the lake this weekend.

The Midwest Medical Examiner’s Office will perform an autopsy to determine the exact cause of death. The case remains under investigation.