QtCreator hung, can not close application

I was in Qt Designer trying out the different views.
I chose the "text" (editor). I presented an unanchored panel. I moved it around
to see what I could do. At that point the entire application hung.
I could not close it with the system X option nor the "close" option from icon
launch bar. I will try to log off if that does not work I will be forced to reboot.