Officials are blaming a faulty transformer for a power outage that knocked out electricity in downtown Huntsville for about 25 minutes.
Power failed in central Huntsville shortly after 8 a.m. Thursday and wasn't fully restored until after 8:30 a.m. About 20,000 customers were affected.
A spokesman for Huntsville Utilities, Bill Yell, said an electronic sensor detected a problem with a transformer. That resulted in the shutdown of an electrical substation near the city's main library.
Tests are being run on the transformer to determine the cause of the problem.