Police say they believe a nanny at a luxury New York City apartment building has stabbed a TV executive's two small children to death and stabbed herself.

They say dad Kevin Krim was away on a trip and their mother found them in a bathtub after returning home with another child.

Police say mom Marina Krim arrived at the dark apartment near Central Park on Thursday evening and initially thought the nanny had taken the children out. He says when she looked in the bathroom she saw 1-year-old Leo and 6-year-old LuLu dead.

Police say the nanny was on the bathroom floor with stab wounds to her neck and a kitchen knife was nearby.

The nanny is hospitalized in critical condition and is in police custody.

Neighbor Rima Starr says she heard someone screaming, "You slit her throat!"