Robert Hodges, 33, was arrested for the murder of his three children at an apartment in West Sacramento.
Another call came in reporting that the children might have died while police were on their way to the apartment, Kinney said.
The mother did not see Hodges kill their children, though she was "in close proximity" at the time.
Police activity will be ongoing in the area through the night and into the morning hours.
She said the grandparents have yet to speak to Hodges or his wife. At first, police had said that Mai witnessed the murders, but now they say she was nearby outside. "The officers are absolutely impacted, along with the firefighters, and certainly the family, the neighbors". "This [investigation] is going to take not hours, not days, it's going to take a long time a long time to come to grips with what happened there".More news: Pakistan beat World XI in 3rd match to seal Independence Cup
"In a small town, each of us, whether parents, neighbors, mentors, and just plain citizens, know that protecting our children is our most sacred duty, and the betrayal of that duty in the home is unfathomable and unconscionable", Cabaldon wrote.
He continued: "It's horrific and it's very hard to deal with".
Speaking to kcra, local resident, Theresa Bustamante expressed shock of news of the triple homicide.
Pictured the three children, Robert Hodges of West Sacramento is alleged to have murdered.Pictured West Sacramento apartment complex, Timbers Apartments, where Robert Hodges is alleged to have murdered the three children33 YO Robert Hodges has been arrested, accused of murdering 3 kids behind the door of apartment 44 at West Sacramento's Timbers Apartments.More news: RED SPARROW First Trailer: Jennifer Lawrence, Russian Sex Spy
"We don't understand what happened, we really don't", she said. (These apartments are) so quiet. "I was in my apartment all the time". They also have not revealed their ages or genders.
Around midnight, the California Highway Patrol noticed the suspect's vehicle on westbound Interstate 80 near El Camino. Grief counselors will be made available to students in the school district, according to reports.
Alina and Daniel Vertelnikov, who are friends of the victims, recalled how happy the kids seemed.
A candlelight vigil is scheduled on Thursday evening for the three victims, which include an 11-year-old boy, a 9-year-old girl and an 8-month-old infant boy.More news: South Korea confirms traces of radioactive gas from North Korea's nuclear test