Five people died in the construction of the Sears Tower, currently called Willis Tower, in two separate incidents in April 1973. The building of Willis Tower started in 1970, and it was completed in 1973.
On April 11, 1973, a fire started around the 42nd floor of the building in the elevator shaft. The fire may have started when cleaning solution came in contact with live electricity, sending flames through the shaft, resulting in the death of four workers. Just days after, on April 14, 1973, 28-year-old Jack De Klerk fell 35 feet after an iron cable knocked him off a platform on the 109th floor. He died before hitting the ground, crashing into steel beams stored on the floors below.