Hydro One crews responded to a major power outage that knocked out lights for thousands of customers from Grand Bend to St Marys.
The outage affected customers as far north as Zurich and Hensall, and to the south near Strathroy.
According to Hydro One, over 12,000 customers were affected by the outage.
As of 4:45 p.m., power had been restored in most communities, although over 5,000 customers around Grand Bend, Zurich and Dashwood are still being impacted.
Hydro One has no estimate for when power will be fully restored.
To get updates, visit the Hydro Stormcentre outage map.