Defective equipment is listed as the cause of a power outage that impacted 3,300 Bluewater Power customers in Sarnia's downtown and surrounding area Thursday afternoon.
The outage occurred shortly before 4 p.m. in 35 Celsius heat with a humidex of 42 C, 108 F.
The utility had all but about 400 customers back on line in about 20 minutes and service was fully restored within an hour.
The affected area was generally south of London Road to just south of Confederation Street, and from the waterfront to just east of East Street.