POTTER COUNTY, TX (KFDA) - Autopsy results received Wednesday confirmed four minors were killed by overexposure to aluminum phosphide.
The Balderas children - Felipe, 7, Johnnie, 9, Josue, 11, and Yasmeen 17 - all had "multi-organ" failures due to the toxic gas released from the pellets placed underneath their house, the autopsy said.
The pellets were placed to control pests, according to the investigation.
Multiple agencies responded to their home on Carolyn Street early Jan. 2 and found one victim deceased upon arrival. All nine household members were taken to an area hospital.
Some family members reported trouble breathing the day before.
Pellets of the material slowly released a colorless gas under their home in northeast Amarillo, and the rate increased when a family member tried to wash them away, according to the report.
Aluminum phosphide is considered a "highly restricted" chemical. Police have yet to say how the chemical was obtained.