Power was knocked out for thousands of homes and businesses in southern Jefferson County Friday morning.

Power is out for 8,100 National Grid customers in the towns of Adams, Hounsfield and Henderson.   Officials say there's a problem with the Coffeen Street substation.   A National Grid website predicts power will be restored for most customers by 8:15 a.m. Some in the town of Hounsfield are expected to be without power until 9:45 a.m. Some customers in the town of Worth should have power back by 10 a.m.   Officials are asking motorists to be cautious because traffic lights might not be working.