LAHORE, April 29: The Water and Power Development Authority's distribution system suffered a major breakdown on Thursday, affecting power supply to a vast area, spanning from Islamabad to Okara.

According to Wapda officials, a major electrical fault developed in one of the three transformers at Sheikhupura's 500kv grid station at around 2.05pm. It overloaded the remaining two transformers, which tripped.

It triggered a chain reaction in the system and the Mangla power house tripped with a 500kv line connecting Multan to Lahore. Power supply to Islamabad, Gujranwala, Sialkot, Sheikhupura and parts of Lahore was restored at 3.15pm and the system became normal at 4.05pm.