The same thing happened to me a week and a half ago on my commute home, the only difference is that I was more fortunate. I was just coming to a stop at a red light when the right side came off in my hand. I ended up with a good size bruise on the inside of my left thigh from the frame slamming over, no other damage to me. It was funny because I was still squeezing the brake in my right hand with the loose section of handlebar. If it had happened a few moments earlier, I would hate to think of what would have happened. Based on the amount of force that the frame went into my left thigh, I think I could easily have veered left into traffic, and there was a bus that had just passed by me on the left.

By looking at the pics below, you may notice that there may have been an advance warning sign that went unnoticed. There is a darker area along the fracture where the fracture has oxidized. I think this must have been an existing crack in the handlebars that went unnoticed.

I have had these handlebars on this bike since the mid 1990's. I did not feel anything prior to the catastrophic failure. I think considering the handlebars a consumable is a really good idea that I would not have considered before this happened to me.

My bike frame is steel, and I'm glad. After seeing this happen, I don't think I'll buy an aluminum frame...