Three children and their grandmother died in a house fire last week near Houston during a power outage as historic cold weather swept Texas, according to local officials.
Firefighters arrived at Jackie Pham Nguyen's home shortly after receiving an emergency call around 2 a.m. on Feb. 16, according to Doug Adolph, a spokesperson for the city of Sugar Land.
The structure was already "engulfed" in flames, Adolph said, with Nguyen outside the home. Nguyen, the mother of the three children, "had to be physically restrained from running back into her burning home," Adolph said.
After dousing the blaze, firefighters found the bodies of three children and their grandmother.
Adolph said their neighborhood had been without electricity for hours and that the family had posted to social media that they were lighting their fireplace to stay warm in the dark.
However, Adolph cautioned that the investigation is ongoing. "We have not yet identified a cause of the fire, and it's possible we never will," he said.
In an interview with CNN, Nguyen remembered her children, 11-year-old Olivia, 8-year-old Edison, and 5-year-old Colette, as "phenomenal, amazing, little badass humans," and her mother as a refugee from Vietnam who arrived in Kansas with nothing, sacrificed much for her children and whose love was "tenfold when it came to the grandkids."
Jackie Pham Nguyen did not immediately respond to a NBC News request for comment, nor did Nathan Nguyen, the children's father.
This story first appeared on NBCNews.com.