MINNEAPOLIS (AP) -- Federal prosecutors say a Minnesota couple accused in the drowning death of their 21-month-old son left their two children unsupervised for nearly two hours.

The Hennepin County Attorney's Office says 25-year-old Sabrina Louis and her husband, 54-year-old Eddy Louis, of Bloomington, were charged Tuesday with second-degree manslaughter for neglect of a child. Their first court appearance is scheduled for Wednesday.

The criminal complaint says the couple left the house before 8 a.m. Saturday and went shopping at Cub Foods and Walmart. They told police the children were asleep at the time and they thought the kids would continue to sleep until they returned.

When the couple came home, they said the oldest child was still sleeping but they heard the 4-year-old in the bathroom, where they discovered the baby in the tub.