As word spread about the impromptu gathering, more than 50 people gathered at Oquirrh Hills Elementary School in Kearns. They shivered in the cold, held candles and sang hymns in honor of the Powell children.
"Whenever a child dies a violent death and an early death, every child has a right to have somebody come out and remember them for who they were and who they should have been allowed to be," Miller said. "I have never met any of the Powells, but I was heartbroken today. I sat down and I cried."
In Washington state, mourners also gathered, including the Powell children's aunt, Denise Cox.
At Carson Elementary School, where the oldest boy Charlie attended school, mourners places stuffed animals, balloons and candles in front of the school's sign.
"He knew he was done for, but why'd he have to take them with him?" Cox asked.
"This isn't fair," she sobbed. "I don't know where my sister is and now my nephews are gone."
Cox remembered the boys trick-or-treating on Halloween after her parents gained custody of them last year. Both boys wore Transformers costumes Charlie in red as Optimus Prime and Braden in yellow as Bumblebee.
Back in Kearns, Stormee Ryan and her friend Shayanna Smith, both 13, attended the vigil and huddled together in the crowd. Ryan brushed tears from her cheeks.
While the majority of the crowd in Utah included people who didn't personally know the Powells, Kiirsi Hellewell and her family, who were the Powells' neighbors in West Valley City, participated in the vigil.
Hellewell said Jennifer Graves, Josh Powell's sister in West Jordan, was too upset to appear at the vigil but was touched by the kindness of those who organized the event.
Hellewell said she has found solace by believing the boys have been reunited with their mother.
West Valley City Mayor Mike Winder echoed Hellewell's comments at the vigil, saying the boys are now "sweetly in the arms of their mother."
"We've seen the embodiment of evil today, and that is Josh Powell," Winder said. "Not only taking his own life, but that of two innocent children. He's been suspicious in this all along. ... Checking out the way he did, dragging two kids with him it's tragic. I think Josh could feel the wagons circling, and he did what he did today."
Winder vowed that the West Valley City Police Department will continue to search for answers in the Susan Powell case.
Miller hopes Sunday's vigil will help the community find closure.
"I take this as an admission of guilt from Josh Powell that yes, he took his wife's life," she said. "He couldn't live with it anymore and if he couldn't have his children, nobody could."