DENAIR (CBS13) – The family of a Denair man and two young boys who died in a weekend house fire say he tried to save those young boys right up until that fire took their lives.

Amber Ortega remembers her younger brother, Sergio Inostros, 25, as having the biggest heart.

READ MORE: Pandemic Causes Shortage Of New A/C Units For Local Companies

She says Sergio was shielding his kids, Mason, 8, and Bennet, 3, when a fire tore apart their home. She says their bodies were found together.

“He’s not just a story, he’s not just a tragedy,” said Ortega.

Sergio’s fiancé, Megan, who is also the mother of the two boys, was working down the street when the fast-moving fire took all three lives. Her aunt, Maria Uballe says she is heartbroken.

“Nobody should be enduring such pain, one alone is tough, imagine three,” she said.

Sergio’s mother reports seeing illegal fireworks above the house about 45-minutes before the fire, but the cause of the fire is still under investigation.

“She says about 30 to 40 minutes before there were fireworks, and from my understanding, that’s been a problem for a few days now or so,” said Ortega.

READ MORE: Young Eagles Are Falling From Their Nests Due To NorCal’s Oppressive Heatwave

Retired fire investigator Frank Romo says it could take weeks before an official origin and cause is revealed. Investigators will rule out any accidental causes first.

But someone reporting fireworks will be crucial to this investigation.

“They’re your eyewitness, the key to the fire report,” he said.

He says the dry conditions we’re seeing right now, make illegal fireworks extremely dangerous.

“All it takes is a spark and it’s gone and you’ve got wind conditions and the fire creates its own firestorm,” Romo said.

Frank says in an illegal fireworks investigation depending on the destruction or if there were fatalities a suspect could face fines or even prison time.

MORE NEWS: Suspect In Custody After Shooting At House Of Oliver In Roseville