Diesel Construction Company was hired as the Sears Tower's general contractor. Sears, Roebuck & Co. chairman Gordon M. Metcalf installed the building's first steel beam at a ceremony on June 7, 1971. The project employed 2,000 workers. To accelerate the building's construction, a concrete plant was built in the building's basement, allowing workers to pour one-third of a concrete floor every day. Contractors built two temporary kitchens on the site for workers, and telephone and loudspeaker systems were installed on every floor to allow workers to communicate. In addition, contractors installed temporary generators that could supply up to simultaneously; during the winter, most of this electricity was used to heat the exposed steel beams on the lowest five floors. Broadcast-signal controversy By late 1971, Chicagoland residents and broadcasters had raised concerns that the new Sears Tower would disrupt television broadcasts. According to one estimate, the building would obstruct television signals for 15 percent of Chicagoans and cause "double images" for another 20 percent, primarily affecting communities to the northwest and southeast. The same year, officials of the village of Skokie, northwest of Chicago, threatened to request an injunction to prevent further construction. In response to these concerns, Sears started researching methods to reduce the tower's effect on broadcast signals. Variety magazine stated that the Sears Tower did not interfere with broadcasts on its own, since several shorter towers in the Loop also interfered with broadcast signals. Nonetheless, the Illinois Citizens' Committee for Broadcasting filed a formal complaint with the Federal Communications Commission (FCC) in February 1972. The first lawsuit against the building was filed by the state attorney in neighboring Lake County on March 17, 1972. A second suit was filed on March 28 in Cook County Circuit Court by the villages of Skokie, Northbrook, and Deerfield, Illinois. Sears filed motions to dismiss the Lake and Cook County lawsuits, which both sought to cap the building at 67 stories. Sears studied the possibility of erecting antennas atop its tower in April 1972, and the tower's construction continued, even as decisions on both lawsuits were delayed. At the end of the month, the company applied for permission to increase the building's height limit by and install a new antenna, although eight of Chicago's ten television stations criticized the plan. On May 17, 1972, Judge LaVerne Dickson, Chief of the Lake County Circuit Court, dismissed the suit, saying, "I find nothing that