Officials say a blaze which began late last week has exploded in size and crossed state borders as firefighters work to contain it. As of Saturday afternoon, the Stateline Fire has burned more than 21,250 acres; about a third of the fire is burning in Colorado. State Forestry officials say "more than 80 personnel from multiple agencies" are working to contain the blaze, whose cause is still being investigated. One "unoccupied" building has burned as a result of the blaze; no injuries have been reported thus far.