David and Crystal Pentecost moved to Edmonton from Manitoba two weeks ago to try to start anew after Dawson's death last year. Police say a man broke into their pickup truck on Friday and stole the necklace and some loose change.
"It's like losing him again," Crystal Pentecost said Tuesday as she pleaded for the jewelry to be returned. "I don't know where it is. It's my son and ... I feel guilty. I should have done more."
Dawson went for his first plane ride on Feb. 10, 2013, with his friends Logan, also 9, and Gage, 10, and their father Darren Spence, who was an experienced crop-duster.
The four died when the plane crashed in a field near Waskada, Man., where the Pentecosts lived. An investigation concluded that whiteout conditions were to blame.
The Pentecosts had cremation pendants made for themselves and for each of their other three sons so they could carry Dawson with them always.
"He was angelic. He was funny, smart, yet quiet," said his mother, who cried as she recalled the loss of her son. "You wouldn't hear anybody say anything bad about him."
Const. Michael Roblin said the thief probably doesn't have any idea what the necklace contains.
"It's a nice-looking chain and I think it was just an opportunity when he saw something nice ... he just went with it."
The necklace consists of a gold-and-silver cross with five crystals running down the front. The cross hangs on a silver chain.
It belongs to Dawson's younger brother and had been hanging in the truck since last May. Dawson's mother explained that he loved his dad's truck and the boy's brother wanted to keep the necklace there so Dawson "could come for all the rides he wants."
"We left it in there and it was never moved until now."
Roblin said police decided to ask for the public's help after hearing from the Pentecosts.
"When they told me what had been taken, it was heart-breaking. It's one of those things that insurance can't cover and you can't replace it," he said.
"They're new to the city and it leaves kind of a bad taste. I wanted to see if Edmontonians can help out."
"We'd just like it back," said Crystal Pentecost. "I'm not angry at anybody. I'd just like it returned.
"It's my son and it belongs to us."
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