07/22/2014 02:17 EDT | Updated 09/21/2014 05:59 EDT

Pendant with Manitoba boy's remains stolen in Edmonton

The family of a Manitoba boy who died in a plane crash last year is devastated after someone stole a cross necklace containing his remains and is asking for its return.

Dawson Pentecost, 9, was among four people killed in February 2013 when a Cessna went down in a field near the community of Waskada in southwest Manitoba.

​Darren Spence, 37, was the pilot of the small plane that was carrying his sons, Logan, 9, and Gage, 10, and the boys' friend, Dawson.

Dawson’s parents, David and Crystal Pentecost, moved to Edmonton just two weeks ago. On Friday, someone broke into their vehicle and stole a cremation pendant containing Dawson's ashes.

“It’s very likely that the thief had no idea about the tremendous sentimental value of this piece of jewelry,” Const. Michael Roblin of the Edmonton Police Service stated in a news release on Tuesday.

“The EPS asks the public to keep an eye out for this keepsake necklace, and anyone with information about the incident is asked to come forward. It is our hope the necklace will be recovered and returned to its rightful owners, even if it is turned in anonymously.”

David and Crystal Pentecost are expected to speak at a press conference scheduled for 3:15 p.m. CT at the Edmonton police headquarters.

The thief failed in an attempt to steal the family's pickup truck, but grabbed some loose change and the gold and silver cross pendant before running off, police said.

The pendant, about four centimetres by two centimetres, contains five crystals and hangs on a silver chain.

Anyone with information is asked to contact the Edmonton police at 780-423-4567 or #377 from a mobile phone.

Anonymous information can also be submitted to Crime Stoppers at 1-800-222-8477 or online.