Bexley, OH – A 74-year-old Bexley woman was found dead today from apparent carbon monoxide poisoning.

The woman, whose name was not released, had collapsed in her cellar at 940 Chelsea Ave, said Columbus Fire Battalion Chief Bill Bishop. The woman’s daughter found her and called 911 at about 6:30 p.m.

Medics discovered carbon monoxide levels of about 600 parts per million when they arrived. The federal Environmental Protection Agency says that normal household levels are below 30 parts per million, and that levels above 150 are can cause death.

Investigators determined that the toxic gas came from a malfunctioning boiler, Bishop said.

The woman lived alone, and had last been seen by family members on Thursday, he said.

More than 400 people die in the United States every year from carbon monoxide poisoning, according to the Centers for Disease Control and Prevention.

“It’s very important for people to have carbon monoxide detectors in their cellars, in staircases and near bedrooms,” Bishop said.