Police in Philadelphia are investigating the death of a newborn baby whose body was found inside a duffel bag.

The infant was found inside a house on the 5800 block of Norfolk Street at 5:28 p.m. Friday, according to police. He was taken to the Hospital of the University of Pennsylvania where he was pronounced dead at 5:59 p.m.

Police told NBC10 the child's 22-year-old mother gave birth to him Thursday and did not take him to the hospital. The woman then went to the Hospital of the University of Pennsylvania Thursday night and complained of pain but did not report giving birth, according to investigators.

The woman's sister went to her home on Norfolk Street where she discovered the child's body and then called police.

Latifah Taylor, the mother's neighbor, told NBC10 the woman moved in less than six months ago.

"They've been very quiet, friendly," Taylor said. "I wouldn't say anything out of the ordinary."

Neighbors said they didn't know she was pregnant.

"Having a child myself, it just hurts my heart to hear something like that," said Ashley Newman. "She could have went another route but I just hope her and her family the best."

The mother is still at the hospital. Police searched through her home to gather evidence. No charges have been filed.