Fontana Police said Jesse Giron, 34, and Irene Carreles, 25, called 911 at 7:30 Thursday morning because their 5-year old daughter had stopped breathing.
"At that time they also saw obvious signs of abuse and neglect. After that they arrested the parents," said Fontana Police spokesperson Martha Guzman-Hurtado.
Police didn't specify what the signs of abuse were.
The suspects were both in jail Friday, facing charges for assault on a child causing death. They were held on $500,000 each.
Three boys were taken into Children and Family Services custody.
Nayelly Beltran lives on the 1600 block of Dorsey Avenue in Fontana, next door to the apartment where the suspects live. She and other adults in the neighborhood have seen incidents of abuse by the couple before.
"Deeply saddened, just that I couldn't be there, that I didn't speak up when I should have," said Beltran. "When the police showed up, we automatically knew."
Beltran says she hopes everyone watching this realizes how important it is to report suspected child abuse.
"I definitely will speak sooner at any other circumstance, and I just hope she's in heaven now," said Beltran. "I'm sorry for what happened to her."