All of Broadway will go dark Saturday and Sunday as Hurricane Irene approaches the East Coast and New York braces for winds, rain and potential flooding during the weekend. It will be the biggest emergency shutdown of the Great White Way since Sept. 11, 2001, and already the city has ordered mandatory evacuations in low-lying areas and will shut down the transit system by noon ET Saturday. Disney Theatrical Productions was the first organization to announce its plans today, saying its productions Mary Poppins and The Lion King wouldn’t run, and the Broadway League followed soon after with its plan. Playbill reports that about 23 productions are affected by the shutdown, including Tony winners War Horse and The Book of Mormon. Major League Baseball also has taken action, postponing a pair of New York Mets weekend games and adjusting scheduled games in Boston and Philadelphia.