A nanny at a luxury Upper West Side apartment in New York Thursday stabbed two children to death in a bathtub, police said. The children\'s mother returned home to the Rochelle apartment building on West 75th Street around 5:30 p.m. EDT to find the two children, a 2-year-old boy and a 6-year-old girl, apparently dead in the bathtub, WABC-TV, New York, reported. They were rushed to St. Luke\'s Hospital, where they were pronounced dead. The nanny, who had self-inflicted stab wounds, was arrested and was in extremely critical condition at the same hospital, police said. Police Commissioner Raymond W. Kelly said the mother, Marina Krim, had taken her 3-year-old daughter to a swimming lesson and left her other two children with the nanny, who was identified as Yoselyn Ortega, The New York Times reported. Krim said she found Ortega, 50, laying on the floor near the knife with a self-inflicted cut to her throat, the Times said.