The fourth person injured in a house fire police say was arson has died, Richmond police announced Saturday.
The woman, who wasn’t identified, was 33. Her 2–year-old daughter died of her injuries Thursday. Her 5-year-old son and her father died soon after the Tue., Aug. 18 blaze on 15th Street and Macdonald Avenue.
“The Richmond Police Department extends its deepest condolences to the family and loved ones during this incredibly difficult time. Our thoughts remain with everyone affected by this tragic loss,” the department wrote in an email to media.
The Contra Costa County District Attorney’s Office on Friday filed murder charges against the woman’s brother, according to a Friday press release.
The four deaths bring Richmond’s 2026 homicide total to nine, according to RPD crime statistics.
The incident is the highest number of deaths resulting from a single instance in recent memory. In 2010 the Mercury News reported that four were killed and four wounded in a weekend of gun violence, but a concerted effort by the city to thwart such crimes proved successful, with 2025 marking the lowest number of murders in its recorded history.
As of Friday, Richmond resident Sergio Ivan Rivera-Vega, 32, had been charged with three counts of murder, with special enhancements, in the deaths of his father Jose Rivera, 47, his niece, 2, and his nephew, 5. Rivera-Vega had been charged separately with arson causing great bodily injury in connection with his sister’s injuries, but it’s likely that will change following her death.
If convicted, the enhancements attached to the murder charges would carry a sentence of life without the possibility of parole.
“This fire is devastating for the entire family,” said District Attorney Diana Becton. “Knowing the suspect is related to the victims — including two children — makes this loss even harder to comprehend this senseless act. Our thoughts are with the family and the community affected by this tragedy. Just know that my office is committed to following the law and holding the suspect fully accountable.”
A GoFundMe campaign has been launched by the children’s aunt, Evelin Rivera, to help cover the family’s funeral costs.
“My mom and I are heartbroken and overwhelmed trying to process so much loss all at once. We urgently need help with funeral services and burial expenses for my dad, my niece, and my nephew,” Rivera wrote on the GoFundMe page last week. “I am currently unemployed, and this tragedy has left us struggling to cover these costs while supporting my mom and praying for my older sister as she continues to fight for her life in the hospital. Anything will help, no matter how small.”
As of Saturday evening, more than $58,000 has been raised.
Rivera-Vega was arrested at the scene shortly after officers began investigating the fatal fire, which occurred in the 200 block of 15th Street two doors away from another house fire that was reported about 30 minutes earlier at another residence that was unoccupied at the time.
Police said that detectives identified Rivera-Vega as the person who set the second fire and took him into custody at the scene while he stood just beyond the yellow police tape.
According to a report by NBC Bay Area, Rivera-Vega was recorded on a nearby camera shortly after the fire at the Richmond Eats building nearby, on the corner of 15th and Macdonald Avenue, flipping benches before sitting down next to a telephone pole.
According to authorities, the earlier fire was set by a woman who was arrested Wednesday morning, though police believe that the incidents are unrelated. They did not identify her.
“At this time we firmly believe that these are two isolated incidents,” said Richmond police Lt. Joseph England. “We have no evidence to believe that our (homicide) suspect was involved in the first fire.”
England said that the first fire is “still under investigation” and that authorities do not know what led to it.
Police Chief Timothy Simmons, who spoke at a press conference Tuesday on the steps of city hall, said that authorities immediately considered the second fire suspicious due to its proximity to the first fire.
“It occurred a few houses away from the first fire and began within a short period of time while emergency personnel were still responding to the original fire,” Simmons said, adding that there is no longer any immediate danger to the neighborhood as a whole.
The first fire was reported on 15th Street between Macdonald and Bissell avenues at about 8:16 p.m., according to fire officials. About 30 minutes after firefighters put out that blaze, Richmond fire Chief Aaron Osorio said, they noticed smoke coming from a second home and discovered the four people inside. They were taken to the nearby Kaiser hospital.
Osorio said that the second fire prompted a larger response by multiple agencies including the El Cerrito Fire Department and Contra Costa County Fire Protection District.
Police said that the injuries sustained by the victims who died appeared to be from the fire though the actual causes of death have yet to be determined.
Police responded to an assault call on the block 30 minutes before first fire
According to RPD incident reports reviewed by Richmondside, Richmond police were on the same block just before 7:30 p.m., 30 minutes before the fire reportedly started, for an incident involving an assault with a deadly weapon that is not a firearm and criminal threats.
England declined to answer questions related to prior calls at the location and said that detectives are still investigating any previous contact officers might have had with Rivera-Vega.
Rivera-Vega is scheduled to be arraigned on Monday afternoon in Martinez. He remains in custody in lieu of $2.5 million bail.
This is truly heartbreaking news. My thoughts are with the child’s family and everyone affected by this devastating loss. Communities coming together to support families during difficult times is so important. Barakah In Kindness is committed to supporting vulnerable communities through humanitarian aid and practical assistance.