BUFFALO, N.Y. (AP) — Millions of people are hunkering down in a deep freeze overnight and early morning to ride out the frigid storm that has killed at least 18 people across the country. The Arctic blast has trapped some residents inside homes with heaping snow drifts and knocked out power to scores of homes and businesses. The scope of the storm has been nearly unprecedented, stretching from the Great Lakes near Canada to the Rio Grande along the border with Mexico. The National Weather Service says about 60% of the U.S. population has faced some sort of winter weather advisory or warning, and temperatures plummeted drastically below normal from east of the Rocky Mountains to the Appalachians.