According to eye-witness reports, and local TV news, bystanders from nearby businesses and vehicles rushed to help most of the injured passengers out of the burning wreckage. The fuselage had separated from the tail section (by at least 10 metres) and was on fire beside a busy airport access road; the tail section was not visibly burning (from news helicopter coverage while still daylight, the accident happened just before sunset here).
News reports said that nine persons were pulled out of the wreckage, five went to the main Vancouver hospital (three in critical condition) and four went to the Richmond hospital (all in stable condition). Some reports say that it has not been confirmed but rumoured that one of the critical injuries has since passed away. Witnesses said that the plane came in at a sharp angle (wings to ground that is), clipped a light standard and narrowly missed vehicles on the four-lane roadway near a busy intersection, then slid to its final resting place while buckling apart. Emergency crews had to extricate at least one person that bystanders could not reach, but it sounded like the quick actions of these witnesses saved lives as flames spread.
Weather in this area at the time of the take-off and return to the airport was likely not a factor, it was partly cloudy with light winds and about 10 degrees Celsius. I would imagine bird strike might be a factor to consider, no evidence of that to my knowledge.
This incident occurred close to the "south terminal" at YVR which is some distance from the main airport and used by short-haul flights; the plane was apparently trying to return there. As a result, while traffic around YVR has been extensively snarled, the main airport remains open and operations are close to normal.
It seems relatively providential that people survived this crash landing and that no vehicles were struck on the road.