Here in TO, in a highrise building; very scary. I couldn't get my balance and felt odd, so went to investigate and the plants on the TV were shaking like mad. The water in the toilet bowl was rolling and I heard loud thumps on the walls-like something had slammed into building. Heard folks out on their balconies exclaiming, "Did you feel that???". Paranoid, I thought initially it was somehow connected to the G20 Summit and others thought it was perhaps a sonic boom created by the G20 security helicopters flying overhead.
Registered 5.5 on the Richter Scale and duration approx 30 seconds. Huge amount of territory felt the tremors.