The two little girls were left on the side of a busy road, dressed warmly in hooded coats and boots and clutching clean diapers.
Dioni, 3, told police that her mother had left her and her sister, Dominae, 2, there and had driven off in a car, but she couldn't say why. The girls were on the Brooklyn street corner for at least 20 minutes Sunday, police said. Two women noticed the girls on the side of the road at about 3 p.m., stayed with them and called 911.
New York Police Department Officers Edgard Centeno and Billy Morales took the call and headed to the scene. The sisters were calm but huddled close together, they said.
"They were sticking by each other very close. They were I guess a little afraid that they were alone," Centeno said.
Dioni was wearing a brown coat, jeans and boots. Her little sister was all in pink: puffy pink coat and pink pants.
The officers took the little girls by their hands, walked to the nearest apartment building, at the Bay View Houses public housing, and asked whether anyone had seen them before.
"Our main concern was just to see who cared for the little girls," Centeno said. "Our main focus was trying to determine who would leave the girls here whether it was a mistake or done on purpose."
The officers had no luck at the building, where none of the longtime residents recognized the sisters. They took the girls by ambulance to a hospital as a precaution.
"They said that they wanted to go home," Morales said. "They said they didn't want to go to the hospital, they wanted to go home."
Meanwhile, detectives were working to find the girls' mother. They had little to go on: The girls didn't know where their home was -- they had said they lived in a blue house with flowers out front, but that wasn't exactly right. They didn't know their mother's last name.
Working with the Administration for Children's Services and with the woman's first name, they tracked down her address, which turned out to be about a dozen blocks from where the girls were left. It was a three-story building with a blue door, part of another public housing system called the Breukelen Houses. Detectives arrived at the home, but the mother wasn't there.
Through an intermediary, the detectives let the woman, Dalisha Adams, know they were looking for her, and she surrendered late Sunday night, police said.
Adams, 26, has been charged with child endangerment. She was in custody Monday and was unavailable for comment while awaiting arraignment. She also has an 8-year-old girl, who was with an aunt at the time.
Police say it's unclear why Adams left the girls, whose abandonment was first reported in the Daily News.
Neighbors said that they could hear Adams arguing often with a man, believed to be her husband, and that she wasn't especially friendly with other residents of the apartment complex.
The little girls are in the custody of child welfare officials, who are investigating the case.