A California mom has been charged with murder for allegedly drowning her 7-year-old daughter, prosecutors said.

Graciela Castellanos, 37, allegedly killed her daughter at an apartment in Van Nuys on April 11, according to the Los Angeles County District Attorney's Office.

A neighbor told Los Angeles ABC station KABC that she heard the girl screaming, "Mommy, please no."

First responders pronounced the 7-year-old dead at the scene, prosecutors said.

Los Angeles County District Attorney Nathan Hochman called the allegations "profoundly tragic and deeply unsettling."

"Our sympathy goes out to the family and loved ones of this young girl, whose life was cut short far too soon," Hochman said in a statement Tuesday.

Castellanos pleaded not guilty on Tuesday to charges of murder and assault on a child under 8 years old causing death. She's due to return to court on June 17.