Authorities in California say a baby girl is dead and her older brother is recovering from serious injuries following an incident during which their mother jumped from the second floor of a residential building recently.

According to KNBC, the incident occurred shortly after noon on Tuesday at a location in Inland Empire.

Emergency personnel responded to the building after receiving reports that a woman tossed a child from a balcony on the second story before leaping from the platform herself.

One witness said she heard a commotion but was not prepared for what had actually transpired.

“She was screaming, and then she threw something,” Yolanda Tapia said. “I never thought it would be a baby.”

A statement from the Upland Police Department indicates the mother went on a short time later to jump from the balcony. She hit the ground below and was transported from the scene to San Antonio Hospital for treatment.

As of the latest updates available, her condition had not been released.

The boy she allegedly tossed from the balcony was listed in stable condition at Loma Linda Hospital. He was identified only as a child over the age of 1.

Officials reportedly discovered an unresponsive girl under the age of 1 inside an adjacent residence. She was transported to the same area hospital with what reports describe as trauma to her upper body and was pronounced dead shortly after she arrived.

Upland Police Capt. Marcelo Blanco identified the woman as the mother of both children, adding that she is about 20 years old, as reported by KTLA.

As of the latest police updates, the investigation remained ongoing and additional details were not available.

[Featured image: video screenshot]