MINNEAPOLIS (AP) - More than 500 people were sickened by carbon monoxide in Minnesota last year and 22 others died from the odorless gas.

The Minnesota Department of Health says the deaths are the highest number since at least the 1990s. The 514 poisoning cases reported to the Minnesota Poison Control System are up nearly 30 percent from the year before.

In the latest case, 53-year-old Lisa Marie Kantorowicz and 56-year-old Cheryl Carmel Adams were found dead of carbon monoxide poisoning in their Lindstrom home Monday. Officials say the home's furnace was clogged and the vents were covered with ice outside. The women did not have a carbon monoxide detector.

Lakes Area Police Chief Kevin Stenson says it's tragic because the deaths could have been prevented with a detector.