Firefighters make progress against NorCal fire that closed I-5

REDDING, Calif. (AP) Higher humidity and calmer winds have helped crews make progress against a wildfire along Interstate 5 in the Shasta-Trinity National Forest in Northern California.

The Salt Creek fire near the community of O'Brien about 16 miles north of Redding has consumed 900 acres and forced the evacuation of about 100 homes. It was 30 percent contained as of Friday morning.

US Forest Service representative Don Ferguson said some residents were allowed to return their homes on Thursday, but most of the evacuations remain in place.

The fire is also threatening 20 commercial buildings and 100 other structures. One outbuilding has already been destroyed.

The blaze began in the median of I-5 on Wednesday afternoon and is believed to have been sparked by human activity.

Fergunson said crews are concerned about lightning strikes from thunderstorms forecast for Friday afternoon.

Copyright 2012 The Associated Press