The investigation into a 100-ft-tall boom lift that tipped over in downtown Kansas City, Mo., may drag on for several months, say officials with the U.S. Occupational Safety and Health Administration. “At this point, we are not seeing any obvious reason why the accident occurred,” says Donna Robertson, OSHA’s acting area administrator. On Nov. 10, two workers for Detroit-based Midwest Steel were elevated inside the basket to place beams at the $405-million Kauffman Center for the Performing Arts. After the lift suddenly tipped over, one worker died and another was seriously injured. Under statute, OSHA has six months to levy
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.