- THE MAGAZINE
The most seriously hurt was the cleaning service employee, who lost consciousness on the building's third floor. Someone called 911 about 11:15 a.m., drawing a cavalcade of fire engines to the 18-unit building in the 12500 block of 35th Avenue Northeast, just east of Lake City Way.
The employee, along with eight residents, was taken to Harborview Medical Center, where his condition was unknown Monday afternoon. Four firefighters also went to the hospital for examination, Seattle Fire Deputy Chief Mike Walsh said.
Many of the civilian patients complained of headaches and dizziness, Walsh said. Three other residents had symptoms but declined to be taken to the hospital, he said.
The carpet cleaner was running a gas-powered generator in his van, parked in the building's garage.
A lack of ventilation allowed carbon monoxide fumes to waft into the building. Investigators were checking whether the garage door had been closed, Walsh said.
Carbon monoxide is a colorless, odorless gas that is produced from partial burning of fuels and can be inhaled without irritation. Carbon monoxide poisoning often manifests in symptoms of dizziness, headaches or nausea and can result in death.
"It could have been disastrous, absolutely," Walsh said. "We're all pleased that it was as small of an incident as it was to what it could have been," he said.
Carbon monoxide levels reached 1,000 parts per million in some parts of the building, well above a safety threshold of 35 parts per million. Firefighters were monitoring the building's air quality afterward, Walsh said.
It was unclear who called 911.
Firefighters went door-to-door, checking which residents had been sickened. Police closed off the block to traffic.
Jason Khan, who lives two buildings away, said he heard the sirens and watched as fire engines stopped along his street. He saw firefighters open a manhole cover and assumed it was a gas leak and quickly ran out his own building.
"I was thinking it's a gas leak or a terrorist attack -- either one," he said.