Seattle teen died from carbon-monoxide poisoning

The King County Medical Examiner's Office has determined that a 16-year-old girl whose December death was investigated by Seattle homicide detectives died from accidental carbon-monoxide poisoning.

Sloane Madison Dwinell, a junior at Seattle Academy of Arts and Sciences, died Dec. 29 in a home that she shared with her mother in the 200 block of Alaskan Way South.

According to the Medical Examiner's Office, Dwinell died of toxic asphyxia after inhaling carbon monoxide from the exhaust of a gas water heater.

Police said the girl was found unconscious by her father, who had gone to the mother's house when he was unable to reach his daughter by phone. No one else was home at the time.

Detectives initially investigated the girl's death because the cause was not immediately known.

Dwinell also attended the French American School of Puget Sound and Seattle Girls' School. She was described as an accomplished pianist, artist and dancer in her obituary.

Her family could not be reached Thursday.

According to James Apa, spokesman for Public Health — Seattle & King County, people with gas appliances should have professionals install them and make sure they are operating properly.

"If you have combustion equipment, like a gas water heater or a gas furnace, it's a good idea to have a carbon-monoxide detector," Apa said.

Most of the incidents of carbon-monoxide poisoning in the region have occurred during power outages, when people have burned charcoal or operated a gasoline-powered generator inside their homes or near the windows and doors.

In December 2006, five members of a Vietnamese family died from carbon-monoxide poisoning caused by a generator that was running in the family's garage after a windstorm knocked out power to the region.

Christine Clarridge: 206-464-8983 or cclarridge@seattletimes.com