Two children were stabbed in New York Sunday, leaving one dead, police said.

The children were attacked around 6 p.m. on Schenck Avenue in East New York, authorities said. The boy, aged 7, succumbed to his injury and the girl, 7, is in a critical condition.

The two children were stabbed Sunday evening by a man on their way to  buy a cold drink near their Brooklyn, NY housing development, reports the The New York Times. They both were attacked inside an elevator at the Boulevard Houses.

The boy, identified as Prince Joshua Avitto, was found near the elevator and the girl, Mikalya Capers, was found injured outside the building, reports NBC New York.

Police said the two children were not blood relatives. But, the Times reported the two were friends since they were toddlers.

The officials said the motive of the attack remained unknown. A knife was recovered at the crime scene.

"He took my pride and joy away," the boy's father, Nicholas Avitto, told the New York Daily News. "I'm devastated. I'm beyond comprehension. I'm trying to understand how God works. My son is gone. That was the light of my life."

No one in connection with the case has been taken into custody. Deputy Chief Patrick Conry said at a news conference that the man took off on foot after the stabbing. He is described as being heavyset and in his 20s, reports the NY Times reports. But according to The Republic and NBC NY,  the suspect is believed to be in his 30s.

 "We all lost a child... This is a happy little boy. This is a pleasant little girl. They were going to get an Icee on a nice warm day... When something happens to one, it happens to all of us," Vice President of the Boulevard Houses Tenant Association, Clara Woods, told NY Times.