Bear Valley, AK – By TATABOLINE BRANT, Anchorage Daily News

A woman whose husband and three children were killed when their Bear Valley home filled with carbon monoxide died Friday morning, relatives and fire officials said.

Rita Arts, 33, had been at Alaska Regional Hospital, where she died, since Dec. 6, when she was found in critical condition inside her Robert Drive home.”She’s joined her family,” her sister-in-law, Heidy Arts, said Friday.

Fire and utility officials, meanwhile, said it was more than just a blocked air vent that caused the deadly gas to build in the Arts home.

Officials said evidence in the house indicated the home’s heating system was shut down during remodeling work and may have created the deadly conditions after it was turned back on.

A mix of circumstances caused the upper floors of the house to suck the deadly gas from the boiler room and spread it around the living area. “There wasn’t any one thing that caused this,” Anchorage Fire Department inspector Greg MacDonald said.

Heidy Arts said in a telephone interview that the Artses’ relatives were appreciative of the support they’ve received. “We cannot stress enough the importance of using safety precautions in your home so this tragedy does not ever repeat itself,” she said, reading from a statement from the families. “Have your heating system checked and serviced on a regular basis. And install and test your carbon monoxide detectors.”

Carbon monoxide, an invisible, odorless and tasteless gas, can cause severe headaches, nausea, confusion and death when inhaled for extended periods of time.

Fire officials would not speculate on whether Rita knew something was wrong and was trying to get her family out of the house. They would only say that everyone in the house was dressed for bed and that Rita was found partially on top of her daughter. The position seemed consistent with Rita carrying the child and collapsing or trying to bend over and check the child and collapsing, they said.

Initial carbon monoxide readings in the house varied by location. On the second floor, they ran from 250 parts per million in the children’s bedroom to 350 ppm in the living room, near where Rita and her daughter were found. The third-floor bedroom where David Arts was found showed 715 ppm, officials said. A level of 150 ppm is enough to kill.

Officials ventilated the house and made a list of all the probable sources of the carbon monoxide. They came up with a vehicle in the garage and three gas appliances: a cooking range, boiler and water heater.

One by one investigators ruled out the range, the water heater and the car. When the carbon monoxide reading in the house was 7 to 8 ppm, an Enstar technician inserted a device into the boiler — and got a reading of 2000 ppm — the maximum the device can detect, Enstar service supervisor Ed Oxborough said. “It was making CO big time,” he said.

Carbon monoxide results from the incomplete combustion of natural gas and other material containing carbon, such as gasoline, kerosene, oil, propane, coal or wood. Soot on a boiler or furnace is a sign of incomplete combustion, as is a yellow flame (blue is normal).

Investigators concluded the boiler was the source of the carbon monoxide throughout the house and were then faced with trying to figure out why the Arts house filled with the poisonous gas when it did, said MacDonald, the fire inspector.

Over the course of a few days, investigators determined that a chimney filled with cold air, a blocked fresh-air intake vent and a malfunctioning boiler all contributed to the CO buildup.

MacDonald said it appears the Arts family shut off their boiler for a short time to work on a gas line that went to a kiln. It is not clear who did the work, he said. Investigators found a receipt for supplies for the job, dated Dec. 4, in the vehicle in the garage, he said.

Officials speculate that this caused the chimney to fill with cold air. Phil Kaluza, an instructor with the nonprofit Alaska Building Science Network, said if that was the case, when the malfunctioning boiler was turned back on,the cold chimney would have made it harder for fumes from the boiler to escape. The boiler’s fresh air intake also was blocked with a cloth, apparently to keep cold air from coming into the house, which further hampered the ventilation, fire officials said.

All this would have caused the air pressure in the house to change, Kaluza said. Essentially, the house started sucking the carbon monoxide-saturated air from the boiler room. MacDonald said investigators used smoke to re-create the conditions and watch the flow of the air.

Friends told investigators that the family had a carbon monoxide detector but had unplugged it. MacDonald said officials never found a detector.

Officials say there are lessons in the situation that took the Artses’ lives:

* Have fuel-burning appliances — such as boilers, fireplaces, water heaters and stoves — and associated exhaust systems, such as chimneys — checked and serviced annually by a professional.

* Don’t block fresh-air intakes; if the vent is causing too much of a draft, call a specialist to come look at it. “Furnace rooms need fresh outside air,” Kempton said.

* Build houses to code, even if you live outside an inspection area. Officials say the Artses lived outside Anchorage’s inspection area, and while most things in their house were up to code, the chimney was not. It was on the outside of the house with no insulation, which helped it to get so cold. “The codes are there to keep you alive,” MacDonald said. “They’re not a bureaucratic exercise.”

* Be aware that exhaust systems — fans above kitchen ranges or in bathrooms, for example — suck air out of a house and that the displaced air must be replaced from somewhere else. If you think your house could be pulling in air from your garage or furnace rooms, call a professional to check it out.

* Install a carbon monoxide detector as well as a smoke detector on every floor of your home. “The bottom line from officials,” Kempton said, “is if you don’t have a carbon monoxide detector, get one. It’ll give you early warning of a very poisonous but odorless, tasteless and invisible gas in your home.”