New York nanny kills children, slashes her own throat

(NBC) - A New York City nanny stabbed a 1-year-old boy and 6-year-old girl to death inside their apartment Thursday afternoon before cutting her own throat.

Police Commissioner Ray Kelly said the children's mother, Marina Krim, returned to her home after a swimming lesson with a third child, a 3-year-old girl.

The apartment was dark when Krim and her daughter entered, and she went to look for her two other children.

"She goes downstairs to the lobby, assuming the nanny may have gone out with the children," Kelly told reporters in a briefing Thursday night. "She asks the doorman if in fact they have gone out, and he says 'No.' She goes back up, the apartment is dark, and she goes into the bathroom."

That's where she discovered her two children, Lucia and Leo, stabbed in the bathtub.

The nanny was on the floor of the bathroom with self-inflicted stab wounds to her throat.

A kitchen knife was nearby.

Neighbors said they heard the mother's screams from her apartment as she called 911.

After police arrived, a neighbor said the mother remained in the building's lobby, screaming hysterically and clutching her surviving child.

The 50-year-old nanny is in custody.

She was hospitalized in critical condition.

The children's father, Kevin Krim, is an executive at CNBC.

Mark Hoffman, president of CNBC, said in a statement that "there are simply no words to convey the magnitude of this tragedy."

"What we can do is come together to express our unwavering support for a friend in need," Hoffman said.

Police have not yet arrested the nanny in connection with the murders, but say they plan to do so once she is out of medically induced coma.