US upper Midwest choked by Canadian wildfire smoke for second year

HELENA, Montana: For the second consecutive year, smoke from Canadian wildfires has forced health warnings across the Upper Midwest and Montana in the U.S.

Fires in British Columbia and Alberta lingered into the morning of May 13, and caused hazy skies over parts of Montana, the Dakotas, Minnesota, and Wisconsin the previous day.

The Minnesota Pollution Control Agency said unhealthy air pollution levels