user: Question: How many viewers, in millions, were for the episode directed by Tawnia McKiernan?
Columns: ['Series #', 'Season #', 'Title', 'Directed by', 'Written by', 'Original air date', 'Production code', 'U.S. viewers (millions)']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [23.0, 1.0, '"Community"', 'Kevin Dowling', 'William N. Fordes', 'September22,2006', '3T5951', '11.94']
SQL:

assistant: SELECT "U.S. viewers (millions)" FROM "Table" WHERE "Directed by" = 'Tawnia McKiernan';