NHK took a picture of the debris flow site in Izusan, Atami City from the sky with a drone around 6:30 pm on the 3rd.
From the video, you can see that the collapsed earth and sand rushed to the immediate vicinity of the road running along the coast, and that the brown muddy water still flows out vigorously, making it look like a river.
You can also see the surrounding houses being buried in the earth and sand that the cars rushed into.