Into the ocean

Date: 2/4/2020

I was in a large mansion-type house, it was red and vaguely c-shaped. A Japanese family lived in this house. I was watching them interact, perhaps they were arguing, when suddenly the floor caved in. I watched from an above vantage point as they all fell into the floor beneath them. Then that floor caved in as well. This happened several more times, until finally the bottom floor caved in and I saw them fall into the ocean which was somehow underneath the ground.