A 71-year-old woman with dementia who went missing three days ago was found dead in a swampy area Tuesday morning, authorities said.

The St. Charles Sheriff’s Office said Anna Mae Chauvin was found near a pumping station at an intersection of drainage canals in Destrehan, news outlets reported.

Investigators said Chauvin was reported missing Saturday. She was last seen at the Metairie mall and the initial search focused on the East Jefferson area until authorities realized she took a cab and was dropped off a few blocks from her home around 10:15 p.m., authorities said.

Investigators said a witness saw Chauvin walking in the area around 2 a.m. Sunday and later that day surveillance video saw her in the same area.

The sheriff’s office asked the Louisiana Search and Rescue team for assistance on Monday, but the search was unsuccessful.

On Tuesday, a private helicopter flew a detective around for an aerial search and around noon, Chauvin’s body was found.

Investigators believe Chauvin wandered in the cold and ran until she died from exposure. An autopsy hasn’t been performed as of Tuesday night.