A mother has admitted shooting her three-year-old son and drowning her four-year-old daughter before taking a bus to a hospital as she had a headache and stomach pains, police said.
Chelsea Thornton, 23, faces two counts of first-degree murder after police said she confessed to the killings at her apartment in New Orleans, Louisiana, where she had moved just a week ago.
The children's grandmother found the bodies of Chelsea Adams, 4, and Kendall Adams, 3, in the bathtub of the home around 5.30pm on Wednesday and immediately called police.
Her son - the father of the children - had told her to check on the children after Thornton had asked him to meet her at hospital as she was feeling sick, The Times-Picayune reported.
When the man, 29, arrived at the hospital to meet Thornton, he asked where the children were, and she responded they were at day care, so he sent his mother to check the home.
The grandmother arrived at the apartment to find the bodies. No one else was there, police said.
Police arrived on the scene after 5.30pm and carried out the children's bodies behind white sheets to the coroner's van as weeping friends, relatives and neighbours swarmed around the house.
'It's a terrible, terrible tragedy,' Police Superintendent Ronal Serpas said. 'It's a very, very sad case.'
Officers swooped on the mother and she confessed to the killings in a taped interview with investigators, they said. She was arrested at 11pm.
The investigation continues as authorities try to unearth what led the mother to kill the children.
A cousin of the children's father, who does not live with Thornton, spoke to reporters outside the apartment on Wednesday and said the couple had had an on-off relationship for five years.
'He tried to help her and help their kids, and other family members also tried to help her,' Nicole Hammons told WDSU. 'You can only go so far.'
'We were concerned for the kids,' she added to the Times-Picayne. 'We obviously didn't know this would happen. All kinds of people tried to get those kids from her.'
Another cousin said when she found out the mother, who does not work, was living with her children in a house with drugs, she said the family could move into one of her rental properties rent-free.
'She had the kids in an environment that wasn't good for kids,' Stella Adams said.
On Thursday, neighbors began leaving stuffed animals around the apartment and said they wished the woman had asked them for help.