A power outage affected almost 1000 customers in Queanbeyan.
The blackout started about 12.30pm and affecting Queanbeyan Hospital, the Riverside Plaza shopping centre and the nearby Kmart.
Power was lost briefly to Queanbeyan Hospital before emergency generators kicked in.
Power was restored to all customers almost an hour later after the outage began.
Essential Energy south eastern operations manager Darren Basterfield said 944 customers had been affected.
"Local crews dispatched to find faulty on the network identified that a tree had fallen on powerlines, damaging network equipment," he said.
Centre management had told stores at Riverside Plaza to remain open despite the outage.
The Coles supermarket in the shopping centre regained power before power was restored to the rest of the shopping centre due to an emergency generator.