A 3-year-old girl weighed only 11 pounds when she died early Monday, according to the Philadelphia medical examiner.

On Tuesday, Philadelphia authorities charged Nathlayz Rivera's parents with the girl's starvation murder.

AP/Philadelphia Police Department Suspect Carlos Rivera.

The girl, who was severely disabled, was found unresponsive in the city's West Oak Lane neighborhood. Authorities ruled her starvation death a homicide.

Police took the victim's father, Carlos Rivera, into custody late Monday afternoon after they spent much of the day searching for him.

Police say Rivera, 30, initially found his twin daughter, Nathlayz, unresponsive around midnight in the family's bug-infested home in the 7300 block of Sommers Road.

"Instead of going to police and the ambulance, he called the mother, who was over at a male friend's house," said Philadelphia Police Captain James Clark. "The mom and friend came to the house, took the baby, and transported her to the E.R. where she was pronounced. The medical examiner ruled this a homicide, manner of death, starvation."

The mother, Carmen Ramirez, was later arrested. Ramirez, 27, and Rivera both face third-degree murder, involuntary manslaughter, criminal conspiracy and child endangerment charges, according to police.

Rivera was arraigned Tuesday morning while Ramirez was expected to be arraigned Tuesday afternoon.

Around 1:45 a.m. Monday police were called to Einstein Hospital since the child appeared malnourished, She weighed only 11 pounds at the time of her death, which is less than half the weight of the average 3-year-old.

The girl "had not seen a doctor in over a year, even with all the severe disabilities," said Clark.

AP via Philadelphia Police Department Suspect Carmen Ramirez.

Investigators say that the twin girl had a chronic disorder and was blind in one eye.

A homicide captain says Rivera fled after leaving four other children with a relative Monday afternoon.

The other Rivera children -- ages 9, 8 and 7, along with Nathalyz's 3-year-old twin -- were being checked at a hospital before being placed with the Department of Human Services.

Later on Monday, homicide and crime scene investigators entered the home belonging to Rivera and Ramirez while wearing protective suits and Hazmat masks. Investigators say piles of trash and insects, including fleas, covered the home.

"If they needed some help, all they had to do was let us know or ask," said Betty Enoch, a neighbor.

"I would never think something like that would happen," said Bianca Stevens, another neighbor. "But I mean, who knows?"