Slip, slide, crash
I was taking it very slow, because we had some snow and ice. I was doing fine on the road, and cut over to a bike trail. There was no way to avoid it, the wheels immediately slipped sideways. I didn't get hurt at all, and nobody was around to drain my pride. It was so slick, I could hardly stand up, and pull my bike vertical. I did fine on the remainder of the 8-mile ride to work.
Several weeks ago I was riding along & realized that my helmet strap wasn't buckled. OK, I'll stop & buckle it. I hit the rear brake and the rear wheel kicks out on me - black ice.
A week or two later I started down the hill I live on and realized there was a lot of black ice, I took it REAL easy that day, but managed to stay upright. You'd think that ice & two wheels would be mutually exclusive, but I guess not necessarily.
If you want to have plenty of traction on ice try studded tires. No help in soft snow, but fantastic on ice.