A power interruption Thursday afternoon at the Forsyth County 911 Center led authorities to use a backup procedure for fielding emergency calls through Friday morning.The Public Safety Complex, which houses the 911 center, experienced a power failure about 3:30 p.m. Thursday while strong storms swept through the area, county spokeswoman Jodi Gardner said.“That resulted in brief, periodic brown outs,” Gardner said. “When that occurred, the county activated the procedures and plans we have in place for these types of situations.”Incoming calls were transferred to the center in neighboring Hall County, which then relayed the information back to Forsyth dispatchers through a dedicated radio channel.Communications switched back to the primary radio on Friday, Gardner said, and the full transition to the 911 center occurred just before 11 a.m.The exact source of the power failure has not been determined, though Gardner said the possibility of a lightning strike or power surge could have been a factor given the thunderstorms.