A brief power outage there resulted in pressure changes at Wallaceburg’s water treatment plant that caused a break in a key watermain. That disruption prompted Chatham-Kent public health to issue a boil water advisory for Wallaceburg while students at the town’s high schools and elementary schools were sent home. Crews were working to repair the collapsed tower, Collie said. The electricity stayed on for Bluewater Power’s customers in Sarnia, but they still may have noticed “a couple dims of their lights” during the morning, McMichael-Dennis said.