Dozens of people gathered at Carson Elementary Sunday evening to place candles, stuffed animals, balloons and messages out front.
The boys, 7-year-old Charles and 5-year-old Braden, died Sunday afternoon in a fast-moving fire at their father's home. Authorities say it's apparent that Josh Powell set the fire deliberately.
Cassie Vermeer, whose son was in the same class as Charles, said she struggled all day to find the right words to tell her kids about the incident.
"I really didn't know how to explain it to them," she said. "I explained what his father did. He will hear it, if not from me, then from other kids or the media so I explained to him about the explosion and that his father took his life and his children's."
Six-year-old David Thompson drew a picture of his friend Charles.
"He was said, he was crying," David said.
His mother Cassie says he drew the picture of Charlie crying, "because he knows he died being hurt... and that's such a terrible thing that would happen to the boys."
School officials said grief counselors would be on hand Monday.
Powell was a person of interest in his wife's disappearance two years ago from the home they shared in West Valley City, Utah. Josh Powell was recently denied custody of the boys, who had been living with Susan's parents for several months, ever since Josh Powell's father was arrested in a voyeurism case.