PORTLAND, Ore. — Bone-chilling temperatures greeted Portland commuters and a derailment near the Rose Quarter caused delays for those who travel by light rail.

The temperature dropped into the teens in Portland overnight and fell below that in some suburbs. The National Weather Service expects sunshine Friday morning, but the mercury may not rise above 30 degrees.

That will slow the melting from this week’s historic snowstorm, and many streets remain a mess.

TriMet, the regional mass transit agency, says an icy track caused Friday morning’s derailment near the Rose Quarter. The train was traveling slowly before the derailment and no one was hurt.

Schools districts in Portland, Beaverton and Vancouver, Washington, are among those canceling classes for a third consecutive day. Bend-La Pine schools are also closed following Thursday’s collapse of a gymnasium roof at an elementary school.