Why won't my Twitter list Delete when I hit Delete?

Created a Twitter list and it will not delete.

It goes through the motions of deleting and I get the message that I can't undo the action of deleting the list, but ultimately it does not delete. I cannot successfully remove people from this list either; it just spins and spins but nothing happens. It's a zombie - it stays around even after I try to kill it. I just want it gone...