Casey the dog

Casey, the 3-year-old Lab that was killed by a cyanide bomb off West Buckskin Road on Thursday. 

POCATELLO — A 14-year-old Pocatello boy watched his dog die from a cyanide poison bomb that detonated near his home on Thursday.

Theresa Mansfield, the boy’s mother, said her son was walking the family dog on a hillside behind their home on West Buckskin Road when they encountered the bomb. When it exploded, the boy was knocked onto his back and the dog was killed.

The Bannock County Sheriff’s Office said the bomb was placed by an individual with the U.S. Department of Agriculture as a predator control device used to kill coyotes. When activated, these type of bombs release a burst of cyanide. 

According to the Bannock County Sheriff’s Office, it is a M-44 device that is commonly referred to as a “cyanide bomb.”

Mansfield said another one of these devices was found near her home after authorities arrived on the scene. 

When Mark, the boy's father, contacted the authorities, he told dispatchers that the dog was dead and his son was covered by an unknown substance. The boy was transported to the emergency room at Portneuf Medical Center to be tested for cyanide poisoning.

The Bannock County Sheriff's Office said he was not seriously injured in the incident and has since returned home to his family. The boy’s family was also evaluated at the hospital and released. 

The Bannock County Sheriff’s Office is investigating the incident. Hazmat crews and fire department personnel responded to the incident, with investigators still at the scene as of 8 p.m. Thursday. 

The deceased dog, a 3-year-old lab named Casey, was covered with cyanide when found.  

"He was the world to us," Mansfield said, saying that her children were openly weeping over Casey's death well into the evening hours on Thursday. 

Both Mansfield and Bannock County Sheriff Lorin Nielsen said the boy was lucky to walk away from the incident. 

“That little boy is lucky,” Nielsen said. “His guardian angel was protecting him.”

The whole incident has completely shaken the Mansfield family. The area behind the residence where the "cyanide bomb" exploded was a location frequented by the teenage boy. Now Mansfield is afraid to allow her children to go near the hill again. 

The incident has also deeply scarred the boy, who Mansfield said saw the dog perish. 

"That is going to be on his mind forever," she said. "Seeing something like that stays with you."

The Bannock County Sheriff's Office released the following statement regarding the incident on Thursday evening:

“The Bannock County Sheriff's Office is investigating an incident involving a predator control device that detonated killing a family's dog. The Sheriff's Office received the call earlier this date from the father indicating an unknown device had detonated in close proximity to his son and the family's dog. The incident occurred on a ridge line located above a residence on Buckskin Rd. The father indicated that the family dog had been killed and his son had been covered in an unknown substance as the device detonated. Luckily this child was not seriously injured. It was later determined that the device was placed at it's location by the Department of Agriculture. The device is used by the Department of Agriculture for predator control and when activated releases a burst of Cyanide. The device is a M-44 device but is commonly referred to as a "Cyanide Bomb". This device is extremely dangerous to animals and humans. A picture of the device in included in this release for the public's knowledge. If a device such as this is ever located please do not touch or go near the device and contact your local law enforcement agency. The family involved in this incident were evaluated at a local hospital and were released.”