A family of four, including two young children, was found dead of possible carbon monoxide poisoning in the town of Parks, Arizona.

The bodies were discovered Monday in a cabin where they were camping, following a request for a welfare check. According to the authorities, a strong odor of gas came from the home before the finding. Ponderosa Fire Department personnel were also called to the scene, a statement by the Coconino County Sheriff’s Office said.

The deceased were identified as 32-year-old Anthony Capitano, 32-year-old Meaghan Capitano, 4-year-old Lincoln Capitano and 3-year-old Kingsley Capitano.

The sheriff’s office received a call at approximately 11:26 p.m. local time Monday (1.26 EST Tuesday) from a friend of the Capitano family. “The caller said family members had been trying to contact them for a few days with no success and had become concerned,” the sheriff’s office said in a statement.

A heating specialist was also called in Tuesday, NBC affiliate KPNX reported. The sheriff's office said the contractor found a "significant failure" in the cabin's heating system. "The heating unit was the only gas appliance in the home. This provides additional evidence regarding a possible carbon monoxide related event,” another statement by the sheriff’s office said.

The Coconino County Medical Examiner's Office was yet to determine an official cause of death.

The sheriff’s office spokesman Jon Paxton said the cabin was owned by a family friend of the Capitanos and was equipped with a gas furnace. “We investigate everything like it’s a crime,” said Paxton. “Right now we are leaning towards accidental carbon monoxide poisoning but we will leave the final decision to the medical examiner’s office.”

The Centers for Disease Control and Prevention (CDC) described carbon monoxide as “an odorless, colorless gas that can kill you.” The most common symptoms of poisoning due to the gas include headache, dizziness, weakness, upset stomach, vomiting, chest pain, and confusion. Breathing in a lot of carbon monoxide could make someone pass out or kill themselves, according to the CDC.

However, Fox affiliate KSAZ-TV quoted Ponderosa Fire Chief Lee Antonides as saying that it was possible to smell a leak from a propane gas furnace.

“It depends on how strong the smell is, how rich and when the furnace was last serviced," he said. “Sometimes you can smell it and sometimes you can't."

Antonides also recommended having a certified heating specialist check the unit before starting it up for the winter.

 “It’s important to, if you’re renting a place you’re not familiar with, to ask when the last time the furnace was inspected,” said Paxton. “Ask if there’s a carbon monoxide detector in the house and if there is, make sure it functions.”

The family was from El Mirage and had traveled to the cabin on Friday night, Paxton said.

“It is my understanding that the family came up late Friday night,” he said. “We believe this may have happened sometime early Saturday morning.”

The CDC also advises annual servicing of heating system, water heater, and any other gas, oil, or coal burning appliances by a qualified technician. Other precautionary measures given by the CDC include:

  • Installing a battery-operated or battery back-up carbon monoxide detector in your home in a place where the alarm could wake you up if it rang,
  • Avoiding the use of portable flameless chemical heaters indoors.
  • Making sure gas appliances in the house are vented properly and not patching a vent pipe with tape, among other that can be found on the website.