The discovery was made one day after authorities recovered the body of another one of her children in Vadnais Lake, which sits just north of St. Paul, according to police.
The body of one child was recovered just after midnight Saturday, the mother’s body at about 10:40 a.m., and the third body was found about 20 minutes later, said Ramsey County Undersheriff Mike Martin told reporters.
The four bodies were taken to the medical examiner’s office, Martin said. The ages of the two boys and one girl were not known.
The sheriff’s water patrol commander, Eric Bradt, said boats are not allowed on the lake, which is about 5 to 10 feet deep.
Police began looking for the mother and her three children — all of whom appear to be under 5 years old — after spotting her car and pairs of children’s shoes near Vadnais Lake.
Authorities believe the deaths are related to a suicide reported earlier Friday around 10:30 a.m. local time. First responders arrived at a residence in nearby Maplewood and found a man deceased, Maplewood Police Lt. Joe Steiner said.
Police responded to the lake at around 4 p.m. Friday.
“This is just a tragic event, and our hearts go out to the family members and the friends involved in this incident,” Steiner said.
Martin said the deaths of the mother and children are being investigated as homicides.