Police say a mother returning to her New York City apartment has found her two small children stabbed to death in a bathtub and her nanny with a knife in her hand.

Scene of shooting on New York's Upper West Side (WABC TV)

The woman found the 3- and 5-year-old children in the apartment on Manhattan's Upper West Side on Thursday evening. Police say the nanny had a self-inflicted wound.

The mother called 911. The nanny has been arrested and hospitalized.

It's unclear how many times the children were stabbed.

The New York Police Department is investigating.
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