The Bootstrap docs indicated that "When using a .close button, it must be the first child of the .alert-dismissible ...".

But actually, the real target selector for the event is .alert.

It seems to me more logical to change the selector in the file alert.js at line number 39 to: $parent = $this.closest('.alert-dismissible')

Thus the .alert class unbinds from JavaScript and allows you to use dismissible alerts without must-have styles from the class .alert. Use only class .alert-dismissible, as described in the documentation.