Localhost: 3000 Install error

[jsengelmann]

When I install the file and click the localhost:3000 link all is well. I can see a demo of the site perfectly. However when I try to close terminal after the steps are complete in installation instructions I receive an alert letting me know that closing the window will terminate running the processes npm (4) and node (9). If I proceed, I receive an error page notifying me that the site can't be reached due to "ERR_connection_refused".

I've tried to install npm and node again separately, but unfortunately it doesn't make a difference. Anyone face a similar issue?