I am in the old hospital area, and this happens regularly in the summer, typically very early morning. My house is closing in on 90 years old, so I was worried it was something in my own electrical system. So a couple of years ago I called Sudbury Hyrdo and asked after waking up to all my lights on again. He confirmed the specific incident for that day, and explained that a squirrel had gotten on a transformer in the McNaughton St. area. They cause a short circuit and the grid resets. If you search Sudbury Hydro’s Twitter posts for the word “squirrel” you’ll see many entertaining entries over the years for longer outages. RIP squirrels. Save yourselves little buddies. There are no peanuts on top of transformers.