Maybe wrong group but idk what this would be under.

So I just moved into my first apartment. My upstairs neighbor is from 400 to 500lbs. He can get around pretty good so I’m thinking he’s still in the 400 range. Well we can hear every step he takes. The floor creaks really bad with every step. Like I know where he is at all times. Should I be worried about him falling through? It’s not just normal footsteps you hear. You can hear the floor sinking when he steps. I’m worried he’ll fall through on my kids. It doesn’t sound like there is anything separating my ceiling from his floor.