For three hours the cause of the stoppage remained a mystery until somebody began to smell a rat.
"We received reports that a large rat had come into contact with an electric rail," Karin Ullman, spokeswoman for power company Fortum, told Expressen.
The rodent was electrocuted in a signal box in the cellar of the Sheraton Hotel, causing a power cut between the hours of 5am and 8am at the hotel, Central Station and a number of adjacent buildings.
All intercity, commuter and subway train traffic was brought to a standstill for the duration of the three hour period.
"It switched everything off. The reason it took three hours was that the fault needed to be exactly localized," said Karin Ullman.