PHOENIX -- Police are investigating the death of a 7-year-old girl whose body was found Friday at a Phoenix apartment complex.

The girl was found dead at the complex near Glendale and 27th avenues around 6:30 a.m. by officers who responded to reports of a child not breathing, investigators said.

The child was with the mother's fiancé when he called 911, officers said. The mother of the child works nights and left the child with her fiancé at his apartment, police said.

"This is being conducted as a homicide investigation until everything is determined from our investigators," said Phoenix police Officer Luis Samudio.

Neighbor Julia Zamora said the family never caused problems. "I've met them," she said. "They've been to one of my sons' birthday parties and they seem like really nice people."