Complex sentence: On the night of the State of the Union, an explosion claims the lives of the President and everyone in the presidential line of succession, except for Secretary of Housing and Urban Development Tom Kirkman, who had been named the designated survivor.
Split into simpler sentences: On the night of the State of the Union, an explosion claims the lives of the President and everyone in the presidential line of succession. Everyone, that is, except for Secretary of Housing and Urban Development Tom Kirkman, who had been named the designated survivor.