BICYCLE INJURIES: What are some other ways a bicyclist can be injured other than from a motor vehicle accident?

As mentioned above, sometimes there is a mechanical defect to the bike itself, or a dangerous roadway.  Or, I have seen in my San Diego injury practice where a bicyclist is attacked by an unrestrained dog or animal, or by another bicyclist or pedestrian in a collision type accident.  Poorly marked trails can also be a potential hazard.