My friend Thomas called me from the ground floor. "There's a bike under the wheel of a car out here. Bring your camera."
It was a scary scene that my eyes beheld. Fortunately and amazingly, it didn't look like any major injuries were involved; the rider was sitting on the curb.
Based on my excellent accident-recreation skills, I'm guessing that the rider was probably headed down the sidewalk, and continued into the crosswalk, and into the path of the vehicle, whose driver wasn't expecting a relatively fast-moving bicycle to suddenly be in her path. The vehicle sent the bike and rider flying; the bike ended up under the wheel. (Thank goodness the rider wasn't under there with the bike. He'll probably ride another day; looked like the end of the line for his vintage Centurion road bike.)
But that's just a guess.
I'll beat this dead horse forever... If a motorist sees you, it's unlikely he'll deliberately run into you. If a motorist doesn't see you, all bets are off. Zipping into a crosswalk can be dangerous; be sure you can clear it.