Rumbles. I remember hearing the 1971 earthquake before it hit as well. That one had a roaring sound. This one I heard when I was in the kitchen. Grab the counter and stood there, then the shaking hit. It was mixed not too jerky, with some rolling. The jerky ones are the most scary because they are hard, fast, and hit in different directions.
It did some serious rolling for sure. Where I lived it threw almost all of the water out of the swimming pool — there was about 2 or 3 inches of water in the courtyard of our U-shaped apartment building.