Jennifer Kimble, 37, was found dead from multiple gunshot wounds by deputies responding to a call from her 8-year-old daughter, the Tulare County Sheriff's Department said in a statement. Kimble's two sons, ages 13 and 11, were also in the house, but all three kids were unharmed.
Deputies also found Kimble's father Anthony Alvarez, 63, dead from what appeared to be a self-inflicted gunshot wound, sheriff's officials said.
Another daughter, Valerie Alvarez, 33, had at least one gunshot wound and was flown to a Fresno hospital in critical condition. She was stabilized and having surgery, sheriff's spokeswoman Sgt. Chris Douglass said.
The investigation was continuing and autopsies were planned later in the week.
Douglass said investigators did not doubt that Anthony Alvarez had shot his daughters and turned the gun on himself.
"It's a very cut-and-dried case," she said.
No information was released on a possible motive.
The children were reunited with their father, who was at work during the shootings, authorities said.
The shootings occurred on a residential street of small stucco homes in Orosi, a town of about 9,000 people in California's Central Valley about 20 miles southeast of Fresno.
Kimble worked in the cafeteria of an elementary school one street over from the house and was a dedicated, caring employee, according to her supervisor there.
"I'm just as surprised as anyone else right now," Brenda Lightfoot-Handy, director of food services at Palm Elementary, told the Fresno Bee. "I'm just trying to process this.