A power line on the mesa broke yesterday evening, causing a power outage for eight to 10 hours from Yucca Valley to Pioneertown. According to County Fire Captain Trent Blanchard, the line broke on Alta Avenue, north of Aberdeen Drive, about 5:30 p.m. About five or six small fires were sparked by the line touching the ground, Blanchard said, but mostly burned themselves out. The power came back on about six hours later, but went back out again later, and didn’t come back on in some areas until shortly before 6 this morning.