A couple and their young son died early Monday morning when fire swept through a home at Briarwood Mobile Home Park in Cloverdale.
At least one neighbor reported hearing a noise "like a bomb going off" shortly before the fire was reported at 1:44 a.m.
Charles Baynes, 33, his wife Paula Baynes, 33, and their 4-year-old son, Philip, died in the fire, Cloverdale police said.
A fourth resident, Charles Baynes' mother, Connie Welch, was in Lake County visiting a daughter, neighbors said.
"It appears to be accidental in nature, we're just waiting to confirm," said Battalion Chief Rick Blackmon with Cloverdale Fire.
The home apparently didn't have working smoke detectors, Blackmon said.
Cloverdale firefighters found the family in a smoke-filled bedroom. They weren't responsive and they were pulled outside where CPR was started at 2:17 a.m.
Charles Baynes was declared dead at the scene. His wife and child were taken from the south Cloverdale home to Healdsburg Hospital, where they were pronounced dead.
Neighbors Monday were shocked and sickened as news of the death of the family spread quickly.
Claire Caudill, a 30-year resident of the neighborhood, said the boy, whom Caudill believed was autistic, was a "very friendly, sweet little boy."
"He always waves and has a big smile on his face," she said.
Tears welled in Caudill's eyes as she realized she still was speaking about the family in the present tense. "I'm going to miss seeing them," she said.
Blackmon said a neighbor called to report the fire.
While firefighters were responding, at least one neighbor was shouting for help, said Caudill, who was awakened by the noise.
"The man next door was running up and down the street hollaring. He asked me if I had a hose," she said, telling him she feared her garden hose wouldn't be long enough.
Cloverdale firefighters haven't had a fatal fire for several years and finding three people, all of whom died, was emotionally difficult, Blackmon said.
"A young child. It is just very tragic," said the veteran firefighter and father, who at times struggled to hold his composure during an interview.
Cloverdale firefighters were dispatched at 1:45 a.m. and arrived five minutes later.
They found a yellow home with white shutters filled with thick black smoke and flames burning the back half of the residence.
It wasn't clear whether anyone was home -- someone at the scene told firefighters the home was empty. But firefighters forced their way inside and found the residents, Blackmon said.
Cloverdale firefighters were assisted by crews from Healdsburg, Geyserville and Cal Fire, totaling eight fire engines and about 20 firefighters.
A Sonoma County fire investigation team responded later Monday morning, aided by Sonoma County sheriff's violent crimes detectives. They combed through what was left of the home to determine what caused the fire and if there was anything suspicious in the deaths, which was not suspected late Monday.
The older mobile home park in southwestern Cloverdale was formerly for seniors only but now residents are a mix of ages. Small yards Monday were bursting with spring color, and at the Baynes home, huge blooming bushes, including a rambling rose, offered a stark contrast to the blackened home.
Neighbors Monday morning came and went, standing at the yellow police line, watching firefighters and investigators sift through the charred remains.