Around 1 a.m. Monday, the power went out, cutting all sources of heat. Rivera dressed in layers and bundled up in blankets as his neighbors sought shelter elsewhere.
"The wind was blowing. Upstairs, it's cold," said neighbor Sammy Hernandez.
"He didn't want to leave. He told me he wanted to stay," explained another neighbor, Juan Garza.
SEE ALSO: Houston grandma who froze to death victimized after her death
Rivera's family found him Wednesday morning. The primary cause of death was hypothermia, according to the Harris County Medical Examiner.
"Gilbert was a happy, friendly, and giving person who will be missed by many friends and family," wrote his sister, Grace Ybarra-Landa, in a text message to ABC13.
Ybarra-Landa said Rivera was mentally disabled but fiercely independent. On Tuesday, Ybarra-Landa and her family spoke to him several times. She said he "sounded great." By Tuesday night, he was not answering his phone. And on Wednesday morning, they went to the apartment on Airport Blvd.
"That's when we found [him] deceased. This is heartbreaking. He did everything he could and that still didn't help," said Ybarra-Landa.
"People died. There's no argument to that. People died. People died because it was cold," said trial lawyer Larry Taylor, managing partner of the Cochran Firm in Houston and Dallas.
Taylor represents the family of 95-year-old Doyle Austin of Acres Homes. Though it is not yet confirmed by the medical examiner, Austin's family believes he froze to death in his home, too. Taylor described him as a pillar in the community.
"He was such an instrumental part in the growth of several young people and we can't let that go unanswered," Taylor said.
Taylor has filed a lawsuit on behalf of Austin's family suing the Electric Reliability Council of Texas [ERCOT] and CenterPoint Energy. It's one of several lawsuits on file. In response, a CenterPoint spokesperson said the company does not comment on pending litigation. An ERCOT spokeswoman told ABC13, "We are confident that our grid operations made the right choice to avoid a statewide blackout."
SEE ALSO: Family of 95-year-old who died during winter weather seeks lawsuit, attorney said
Taylor hopes he and his team can get past the sovereign immunity argument to get answers for families of the more than 20 people who have died in the Houston area after the power went out, those like Doyle Austin and Gilbert Rivera.
"This could have been preventable if the electricity was not off for days," said Ybarra-Landa. "Something could have been done and my brother could still be with us."
Full Statement from ERCOT:
"We haven't yet reviewed the lawsuits and will respond accordingly once we do. Our thoughts are with all Texans who have and are suffering due to this past week. However, because approximately 46% of privately-owned generation tripped offline this past Monday morning, we are confident that our grid operators made the right choice to avoid a statewide blackout."
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