Jay "Tito" Morales was at Weill-Cornell Medical Center, NY1 reported. His grandmother was also hurt in the fire Monday.
"The boy made what we believed to be three prank calls to 911 earlier and it appears now that he did set the fire," said Police Commissioner Raymond Kelly. "He is in critical condition. His grandmother was also taken to hospital for smoke inhalation."
Neighbors in the Bushwick neighborhood of Brooklyn said that Jay was angry because his grandmother punished him.
"I don't know what happened," said Samantha Gordillo. "A couple of kids came by saying that he was screaming in the park he was going to burn the house. A couple minutes later, the house was on fire. I don't know. I didn't get to know the little boy personally. It's a tragedy."
The boy allegedly used a cigarette lighter to set the curtains on fire.