The nanny is arrested in the death of the children, ages 2 and 6, at a luxury New York City apartment

Investigators on Friday are searching for a motive as to why a nanny on New York’s Upper West Side allegedly stabbed two children in her care and then apparently attempted to take her own life.

The nanny, identified as Yoselyn Ortega, has since been arrested, but has not been charged.

Overnight Thursday more details came to light about the stabbings that left a 6-year-old girl, Lucia Krim, and a 2-year-old boy, Leo Krim, dead. The children were found stabbed and bleeding in a bathroom of their Upper West Side apartment by their mother, Marina Krim, when she arrived home at their upscale residence, located near Central Park, with her third child, a 3-year-old daughter named Nessie, around 5:30 p.m. Thursday, the NYPD said.

Neighbors were alerted by her screams and called 911.

NYPD Commissioner Raymond W. Kelly said the mother had arrived home from swimming lessons to find a darkened apartment, and had gone back to the lobby to ask the building superintendent where the nanny and her other children were. He told her they had not left the building. She returned to the second-floor apartment and turned on the lights, only to find the bloody scene, The New York Times reported.

The nanny, 50, who reportedly tried to kill herself by slitting her own throat, was found on the bathroom floor with a kitchen knife nearby. She remains in critical but stable condition, Kelly said. She has no criminal record and had worked for the family for about a year, the New York Post reported.

CNBC, the network where the children’s father Kevin Krim is an executive, released a statement Friday. He had been away on a business trip in San Francisco when he learned of the slayings. But he quickly returned to the city, police said.

“A member of the CNBC family has suffered an unimaginable loss. The sadness that we all feel for Kevin, Marina and their family is without measure. Our thoughts, prayers and unwavering support are with them all,” a statement released by Comcast and NBC Universal read.

The children’s mother had reportedly chronicled their lives in a blog, with snapshots of the children enjoying life all over the city.

In the blog, which has been suspended since the crime, she described the family’s close relationship with their nanny, noting that they had visited the nanny’s own family in her home country of the Dominican Republic, the Times reported.

“We spent the past 9 days in the Dominican Republic. We spent half the time at our nanny, Josie’s sisters home in Santiago,” her blog read, according to an excerpt published in the Times. “We met Josie’s amazing familia!!! And the Dominican Republic is a wonderful country!! More pics to come!!”