Parents have complained to the Telegraph after they were separated from their children when Corby Swimming Pool was plunged into darkness on Saturday night.
A power cut in the centre of Corby also affected the centre, and readers who contacted the Telegraph said emergency lighting around the pool also did not work.
One said: “At about 8.30pm during a swimming meet there was a power cut during the last race.
“The stairwells were dimly lit at best and the whole pool and gallery, holding about 100 concerned parents, was thrown into darkness.
“The six swimmers, aged ten to 12, in the middle of a race and the 100 or so children along the poolside were in pitch black atmosphere.
“It was some two or three minutes before lifeguards had torches from the reception area to poolside to fish the children out.
“This was understandably a very frightening moment.
“I did not know where my child was at the time and it was some 15 minutes before I found her in the dimly lit changing rooms.”
A spokesman for Corby Council said: “Unfortunately, Corby East Midlands International Pool was affected by the powercut throughout the town centre on Saturday evening and issues with the emergency lighting within the building also arose.
“Despite the problem, everyone was evacuated safely and contractors are now working towards resolving the issue to avoid any future incidents.”