A 55-year-old former nanny was sentenced to life in prison for murdering two young children in her care on New York City's Upper West Side. Yoselyn Ortega was convicted last month of killing Lulu, 6, and Leo Krim, 2, on October 25, 2012. Prosecutors described how Ortega used two kitchen knives to slash them to death. Then she placed them in the tub, authorities said. When Marina Kim arrived home, Ortega had sliced her own wrists and plunged a knife into her throat.