The script used to shoot the pilot was virtually unchanged from what Crichton had written in 1974. The only substantive changes made by the producers in 1994 were that the Susan Lewis character became a woman and the Peter Benton character became African-American, and the running time was shortened by about 20 minutes in order for the pilot to air in a two-hour block on network TV. Because of a lack of time and money necessary to build a set, the pilot episode of "ER" was filmed in the former Linda Vista Hospital in Los Angeles, an old facility that had ceased operating in 1990. A set modeled after Los Angeles County General Hospital's emergency room was built soon afterward at the Warner Bros. studios in Burbank, California, although the show makes extensive use of location shoots in Chicago, most notably the city's famous "L" train platforms.