A transformer explosion inside Belco’s Park Road substation caused a power outage that shut down operations at a number of businesses in Hamilton.The incident occurred at 3.18pm yesterday while maintenance crews were working outside on the substation’s second transformer. No one was injured.According to Belco spokeswoman Susan McGrath-Smith “one-fourth of the city lost power, particularly in the northern section between Park Road, Par-la-Ville Road, Church and Reid Streets and Burnaby Hill.Traffic lights in the area were also affected in addition to the Central Terminal in Hamilton. At the 24-hour gas station on Par-la-Ville Road, the lights were out briefly before staff activated the company’s generator.At the Quickie Lickie laundromat a spokesman said customers will be reimbursed but they will have to do their laundry again as the machines shut down in mid-cycle.“Work to restore electricity service to affected customers began immediately, service was restored by 4.30pm,” said Ms McGrath-Smith.The cause of the fault in one of the transformers at the substation was investigated and was repaired. The transformer was returned to service later in the afternoon. Ms McGrath-Smith stressed that the power outage was not related to “increased summer load”.She also apologised to customers for the inconvenience caused by power outage and thanked them for their patience.