Why is the server not completely killed via ctrl-c in the terminal?

Question

Node.js

The problem is that when I want to stop the server via ctrl-c, it closes, but the port is still busy. Therefore, you have to kill it manually
fuser -k 3000/tcp
ps Ubuntu 16.04, normal terminal + zsh
UPD
I'm afraid it's mystical for me, but it cured itself. Although my brain has been soaring for a month now. Apparently the toaster showed its influence;)

Answer 1

Probably because you don't close the connection before killing the server.