LAYTON -- A 4-year-old Layton girl died over the weekend from what's believed to have been exposure to a gas used to kill rodents. Now her 15-month-old sister is in intensive care for the same thing, and investigators still don't know how the gas leaked into their home.

Extermination company defends itself

The extermination company implicated in the investigation of a poisoning death defended itself Monday, saying its technician followed correct procedure.

"I don't tell my technicians to go and do things that are going to be harmful," said Raymond Wilson, president of Bugman Pest and Lawn Inc.

Still, two people have been severely harmed: 4-year-old Rebecca Toone died, and her younger sister, Rachel, is in intensive care at Primary Children's Medical Center. The sisters were poisoned by phosphine gas used to kill rodents outside their home.

On Friday, Feb. 5, Bugman Pest and Lawn treated the front yard and backyard of the home near 1500 North and 2400 West for vole infestation.

The company had exterminated the house with a milder product about two months ago. That didn't get rid of the problem, so an exterminator went back and put Fumitoxin into the vole burrows. The tablets give off phosphine gas and kill the rodents.

"He put the pellets in the ground, plugged the holes with newspaper, and then put dirt over the holes to keep the gas in the ground," Wilson explained.

He insists his licensed technician did everything according to protocol and EPA standards, but he did not know where the tech put the pellets in relation to the home.

Investigators trying to find how gas entered home

Earlier in the day, members of the Utah National Guard's 85th Civil Support Team dug at two locations around the house where an exterminator placed the poisonous pellets on Friday, and found and removed the poison.

According to Layton Fire Chief Kevin Ward, crews are testing to see how much aluminum phosphate was used and how much of the toxic gas may have gotten into the house. When the home was tested Sunday, it had 30 parts per million of phosphine; 50 parts per million is considered deadly.

"We are still at a mystery as to how it actually got into the home, how it leached in. Whether there was a, some kind of pipe or cracks in the foundations, we don't know," Ward said. "We don't even know if the application was done according to the way it's supposed to be done in the first place."

Phosphine gas kills 4-year-old, sickens toddler

At first, the Toone family thought they might have a carbon monoxide leak when several family members started feeling sick Friday and their detector sounded. They called the fire department, which determined there was a small amount of CO, but nothing serious, and the home was cleared.

Then Saturday, 4-year-old Rebecca started having a hard time breathing.

"The mother originally took the 4-year-old to the Wee Care Urgent Care center in belief that this was possibly just food poisoning," Ward said.

Doctors recognized Rebecca's symptoms as much more than food poisoning and transported her to the Davis County Hospital, where she died.

After the girl's death, firefighters went back to the house and determined that the family likely became sick because of the aluminum phosphine that was placed in the ground outside the house. Now Rebecca's 15-month-old sister, Rachel, is in critical condition at Primary Children's Medical Center.

"It (phosphine) just disrupts the function of the cells so that they can't perform their normal bodily functions; and again, our heart and our brain are most affected, as well as the lungs," said Dr. Barbara Insley Crouch, with the Utah Poison Control Center.

The other family members, including two other children, were treated at the hospital and released.

Family issues statement

The Toone family released a statement Monday evening, saying, "We are greatly saddened by the passing of our 4-year-old daughter, Rebecca Toone. ... We have been sustained by the love of our family, friends and neighbors, and by our faith and understanding of our purpose in this life and the world to come. While much is yet to be understood, we respectfully ask for the privacy to mourn our loss and see Rachel's care and some measure of peace for ourselves and our children." [CLICK HERE to read the entire statement from the Toone family]

------

Story compiled with contributions from ngonzales@ksl.com, Jennifer Stagg, Shara Park and Andrew Adams.