[The video seems to be taken from high above ground, as if Bellatrix were showing it from the rooftop of a building.
Far below is a river, filled with the smoldering wreckage of what used to be a large bridge; twisted metal and asphalt break off suddenly over the water, and large chunks of it sit on the shore and in the river. All around are also automobile parts, doors and hoods and tires either sitting on the banks or floating away.
Floating downstream are also a long, unmoving stream of bodies. There are at least a few dozen of them at first glance, some caught against the remains of the bridge and cars, the rest slipping downriver, bobbing at the surface.]
He should have stepped down. They're only delaying the inevitable....and letting more of them die while they wait.