Tucson Fire Department found three people and a dog showing signs of carbon monoxide poisoning in their home this evening. The close encounter with the silent killer was caused by a car left running in the homes garage according to the fire department. The carbon monoxide was able to seep into the home where two teenagers and an older female were found inside. All three residents were transported to the hospital and the family’s dog was treated with oxygen by firefighters on site. Tucson Public Information officer, Captain Andy Skaggs, released a statement warning against the dangers of carbon monoxide poising in the upcoming season.