- Video: 2 children killed in Rialto house fire
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A third child, a 1-year-old girl, and a 54-year-old man remain hospitalized.
Firefighters responded to the 1400 block of North Lilac Avenue and found flames shooting out of the roof of the home just after midnight.
"There was much smoke, we couldn't see nothing," said Irma Delgado, the victims' grandmother.
Delgado said she and her husband were awakened by one of the victims, who told them the house was on fire. Flames and thick black smoke were spreading quickly, as she tried to guide her two grandsons to safety.
"I was just crawling down on the floor, and I thought, like, to show the kids how, and I lost them, and the fire department, they found them in the bathroom," she said, choking back tears.
Firefighters went in and pulled two boys out, ages 4 and 5. They were rushed to a local hospital in critical condition, but later died.
Relatives said the boys were hiding in the bathroom with their puppy.
Delgado's husband tried to go back in the house to rescue their niece's 1-year-old daughter, but it was too smoky.
Instead, he went out around to the back and was able to pull her out through a window, suffering burns during the rescue.
"She came back from the hospital with not a scratch on her. Her lungs were fine. Thank you isn't enough," said Melissa Rosales, mother of the 1-year-old.
One of the problems crews faced as soon as they were on scene was a locked wrought iron fence surrounding the property. They cut a portion of the fence to gain access.
"There were reports of possible victims trapped. We worked as fast as we could to get in there," said Matt Payne from the Rialto Fire Department.
Officials said the four-bedroom house is shared by seven adults and four children, but some of them were not home at the time of the fire.
It took firefighters about 30 minutes to knock down the fire.
The cause of the fire is under investigation.
A memorial fund has been set up for Mario and Davis Cisneros. Donations can be made at any Chase Bank location. Make sure your donation is made out to "Cisneros Memorial Fund c/o Irma Delgado."A car wash fundraiser will be held for David and Mario Cisneros Saturday in San Bernardino from 9 a.m. to 5 p.m. It will be located at A One Auto Center at 333 South Waterman Ave.