participating in the event are at risk; steel hammers [...] are hurled through the air at great speeds, [travel] far distances, and [are] sometimes difficult to spot in flight." For example, hammer throws resulted in four deaths in Europe in 2000 alone, and have caused deaths and permanent brain damage injuries in the United States too.

To mitigate such risks, a C-shaped "hammer cage" was introduced, which is built around the throwing circle, preventing the hammer from flying off in unwanted directions. In 2004, the IAAF