Observations: it is NYC, and the passing bus driver is seated on the left, per Acorn's question. It's an American bus, as well. I can't read the illuminated route indication near the bus front, however.
A camera operator can be seen in the background, on the sidewalk in front of the 6-story tenement. He's aiming at the van's point of impact before it even appears, not at the wrecking ball, as he would do if making a record of the demolition work.
The ball is very low for demo work, and comes to rest in the street, because the boom is swung out. That means the entire street would have been closed off as a routine safety precaution, and parked traffic removed. Nor would the sidewalk have been left open. I presume those pedestrians are stunt people.
The timing to get the ball to hit just behind the driver would be so difficult that I wonder if the van was driven remotely, the risk to a human being too great. A hit in the door would have pushed it in severely, plus even a well padded stunt driver would take enormous G-forces from the sudden lateral acceleration.
I didn't see the mechanical arm that Ganymede80 did. I did see a loose object under the van for a second, but it could be detached trim. I believe the ball did hit the van fully.
Some of the "spectators" on the left were slow to step into the street at first, but then the wrecking ball was still swinging a bit. At the very end of the clip, however, one of them appears to try to grab the ball and steady it. What a strange thing for an ordinary bystander to do.
This would have made a great TV story, especially in light of recent fatal contruction crane accidents, including in NYC. But I saw nothing about it, despite being dated just a month ago. Did any of you?
Conclusion: I think it was likely a planned stunt.