At 11 years old, Olivia Nguyen was the oldest of three siblings. She was smart and sassy, and loved making playlists with songs from Coldplay and U2, music written before she was born.

Her brother, Edison, 8, was quiet and articulate. He loved the colour green and taking photos of anything in his path, especially sunsets.

Their youngest sibling, Colette, turned everything into a song. Nicknamed Coco, the 5-year-old was known for donning sparkly pink dresses and shoes.

Early Tuesday morning, the children and their grandmother, 75-year-old Loan Le, lost their lives when their Texas home erupted in flames. The fatal blaze may have started from a fireplace – which their mother had lit up to keep them warm amid the state’s power outages and freezing cold temperatures.

The Nguyen children and their grandma Loan are among more than 30 people in the Lonestar State who died this week amid the extreme weather crisis that nearly decimated the state’s power grid.

Before the fire, the family was without power for eight hours and huddled together in their two-story house in Sugar Land, a suburb of Houston. It’s unclear how the blaze spread; the bedrooms are upstairs and the fireplace is downstairs.

Vanessa Kon, the children’s aunt, said the family is awaiting answers on what started the house fire. While they’re focused on mourning the kids, they also have questions for state officials who were woefully unprepared for the unprecedented disaster, which left millions of residents without heat, electricity, or water.

“We don’t know what happened,” Kon told The Daily Beast. “We don’t know why the lights went out like that. The city should have been prepared for it. Why was the power off? If the power wasn’t off, this wouldn’t have happened.”

According to Fox 26 in Houston, authorities were called to the Nguyen residence around 2 a.m. and found the house engulfed in flames when they arrived. One fire official said a first responder had to restrain the children’s mother, Jackie, from rushing back inside the home.

The children’s father, Nathan Nguyen, is separated from Jackie and lives in another home in Sugar Land.

Kon and her siblings were comforting Nathan at his house throughout the week and on Saturday. The home, once so dedicated to Olivia, Edison, and Colette, now seemed empty.

The walls are covered in paintings he made with the children. One room has a collection of different paints and canvases so they could make art together. The refrigerator has three tubs of butter because they all loved baking cookies. In Colette’s bedroom, a mermaid costume rested on the bed, along with a pair of dolls.

Kon said Nathan bought matching shoes for himself and his little ones, and he enjoyed wearing matching swim trunks with Edison.

“Everything is about the kids,” Kon said of Nguyen, 41, who is a beloved family physician in a small-town nearby called Wharton. “It’s so devastating.”

Kon said Nguyen is in the process of divorcing Jackie but had custody of the kids every weekend or sometimes more, especially in the summer. He last saw them about a week before they died and was planning on picking them up on Friday.

But on Tuesday morning, Jackie’s brother called with soul-crushing news: There was a fire and all three of his babies didn’t make it. Jackie and a female friend who was staying over had escaped the inferno with minor burns.

“My brother was like, ‘What is this? A joke?’ He didn’t believe it,” Kon said.

“It’s just so sad,” she added. “He only had three [kids]. All three are gone.”

“I really want someone to take this pain away from him, you know. It’s just unbearable for him. It’s so surreal. I can’t believe it’s happening,” Kon told The Daily Beast.

Kon said Nathan is a shining example of a father. She’s never seen him yell or raise his voice; he’s incredibly patient. Last week, he stopped by three different restaurants so all the kids got what they wanted for lunch. “He’s that dad,” Kon said. “He would always plan stuff with them. Always do something. It’s not like they’re sitting at home, doing nothing. He takes vacation with each of his kids separately.”

Now Nathan is planning for a funeral – and the weeks and months that come next.

He hopes to set up a tuition assistance fund for St. Laurence Catholic School, where his kids attended elementary school and a place that they loved.

Kon organised a GoFundMe page to help plant the seeds of the school foundation.

Meanwhile, Jackie’s classmates at Rice University’s business school created another GoFundMe page to support her and future charity in the children’s names.

In a message from Jackie that was posted on the page, the grieving mom said she wanted to create a foundation with themes that would “reflect the kids’ as individuals,” including: performance visual arts, autism awareness, and reading and literacy.

“At the end of the day, we want this all to mean something, and that your kind intentions are also honored in a meaningful and lasting way,” she said. “Our hearts are broken right now. However, your acts of kindness have given us some comfort to pull us through.”

Both Jackie and Loan were dedicated to the children.

Loan loved being close to her grandkids and was actively involved in their lives. She could be found in numerous Facebook photos with Jackie and the children – including proudly posing with them at St. Laurence Catholic School for Grandparents’ Day. She was also often pictured with her son, David Pham, and his kids.

In October, Loan shared pictures of herself and the two sets of grandkids on social media. Edison and Olivia held a pillow with the word “family.”

•Text (excluding headline): Daily Beast.

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