A 3-day old California baby was found dead after being attacked by two family dogs, police say.

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The 33-year-old Fresno mother left the door open around 12:30 a.m. Monday evening "to let some cool air come in the house," Sergeant Daniel Macias from the Fresno Police Department told InsideEdition.com.

She then assumed two dogs in the backyard were chained up before she put her newborn on the couch and left to use the restroom, police said.

According to KGPE-TV, the woman heard her baby, identified as Susie Kirby, screaming moments later. By the time she reached the child, it was too late.

"Unknown to her, the dogs were loose and one of them was able to get inside and ended up biting the infant," Macias said.

The woman's 30-year-old brother, who was the only other person in the home at the time, contacted paramedics.

Baby Susie died shortly after being rushed to Community Regional Medical Center early Monday morning, the same day her mom was due to give birth.

"They were very upset that night, and obvoiusly very distraught over the sitatuion," Macias said.

According to authorities, both dogs were owned by the woman's brother. The dog who killed the infant is believed to be a shar-pei and pit bull mix, and is known to be the "guard dog" of the two.

The brother surrendered the dogs to the Central California Society for Prevention of Cruelty to Animals, where officials said the dogs will be euthanized.

A GoFundMe page was created for baby Susie's burial costs, but was soon taken down.

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Fresno police are continuing to investigate the incident, but no charges have been pressed.

"We believe from all indications that it was an unfortunate accident, but we are looking into any type of child endangerment [or] criminal activity," Macias said.

An autopsy was conducted Tuesday to rule out foul play, Macias said.

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