A 19-year-old mother was arrested Tuesday after her four-month-old baby girl’s body was discovered inside a dumpster in South Los Angeles.

The grisly discovery occurred around 10:30 p.m. Monday near the 5200 block of Alba Street, directly across from Holmes Avenue Elementary School. 

A local resident, Martha Serrano Jimenez, was taking out trash with her daughter when she noticed an unusually heavy black plastic bag inside the dumpster. 

Using a cellphone flashlight to inspect the bag, Serrano Jimenez initially mistook the contents for a doll, exclaiming “una muñeca,” before realizing it was an infant, according to Fox LA. 

Her daughter immediately dialed 911 while Serrano Jimenez, neighbors, and the emergency dispatcher attempted to perform CPR. 

Around 4 a.m. Tuesday, the tot’s grandparents, Herman Johnson and Laura Lacy saw it reported that the dead infant had six toes on her left foot, a trait shared by their granddaughter.

They rushed to Johnson’s apartment in South Los Angeles, just a few hundred yards from where the body was discarded, according to the news outlet. 

“To be found in a dumpster, a dirty dumpster. It just broke my heart. I don’t know what to do, man. I don’t even know what to say,” the infant’s heartbroken grandfather told the news outlet.

When shown a photo of Johnson and Lacy’s granddaughter, Luna, Serrano Jimenez confirmed to investigators that the girl in the picture was the same infant she had discovered in the dumpster.

When questioned, the mother produced a cellphone photo claiming the baby was safe. However, Lacy recognized that it was an old video based on the child’s clothing and spotted the baby’s car seat sitting unused inside the bedroom, reported Fox LA.

LAPD officers cordoned off the apartment unit as a crime scene while awaiting detectives from the Abused Child Unit. Investigators detained the teenage mother shortly after 8 a.m. Tuesday.

The LAPD Homicide and Abused Child Units continue to investigate the circumstances surrounding the infant’s death. Authorities have not yet announced pending formal charges against the mother.

The Los Angeles County Medical Examiner’s Office is working to formally identify the infant and determine the exact cause of death.