Chicago "L" 2014, the "L" had an average of 752,734 passenger boardings each weekday, 486,267 each Saturday, and 359,777 each Sunday. In a 2005 poll, "Chicago Tribune" readers voted it one of the "seven wonders of Chicago", behind the lakefront and Wrigley Field, but ahead of Willis Tower (formerly the Sears Tower), the Water Tower, the University of Chicago, and the Museum of Science and Industry. The first "L", the Chicago and South Side Rapid Transit Railroad, began revenue service on June 6, 1892, when a steam locomotive pulling four wooden coaches, carrying more than a couple of dozen people, departed the
Willis Tower unfinished World Trade Center to become the world's tallest building. The height was restricted by a limit imposed by the Federal Aviation Administration (FAA) to protect air traffic. The financing of the tower was provided by the Sears company. It was topped with two antennas to permit local television and radio broadcasts. Sears and the City of Chicago approved the design, and the first steel was put in place in April 1971. The structure was completed in May 1973. The construction cost about US$150 million at the time, equivalent to $ million in 2019. By comparison, Taipei 101, built in