A 4-year-old girl died at a hospital Tuesday after being pulled Sunday from a house fire in the District, authorities said. Arson investigators have been looking into the cause of the fire.

The girl, whose name was not released, was unconscious and not breathing when found in the house in the Hillcrest area of Southeast Washington, D.C. police spokeswoman Gwendolyn Crump said. Four other people were injured, but all have been released from hospitals after treatment.

Police and fire officials said the cause of the fire, in the 2600 block of 33rd Street, could take time to determine.

“It was blazing,” a neighbor said of the fire, which was reported shortly after 3 a.m. “The whole house was in flames.”

The neighbor said he understood that the girl lived there with relatives. He recalled seeing them taking her by bus in the morning to preschool classes.

The house, within a few hundred yards of the residence of D.C. Mayor Vincent C. Gray, (D) appears to be uninhabitable, the neighbor said.

Authorities said they think the death was the third fire fatality in the District this year.