At 1129 hours this morning, a monkey climbed on the roof of Gitaru Power Station and dropped onto a transformer tripping it. This caused other machines at the power station to trip on overload resulting in a loss of more than180MW from this plant which triggered a national power blackout. The system has since been restored and all our power generating units are operating normally. KenGen power installations are secured by electric fencing which keeps away marauding wild animals . We regret this isolated incident and the company is looking at ways of further enhancing security at all our power plants.