A 42-year-old laborer leak testing joints inside a 54-inch round pipe suffered fatal blunt force injuries in October 2015, when an inflatable “bladder” ruptured at a Springfield waste-water treatment plant. OSHA inspectors found that his employer, Henderson Construction of Central Illinois Inc., failed to train him properly on the testing procedure.

The agency also cited Henderson and three other contractors working on the $54.4 million renovation of the Springfield Metro Sanitary District’s Sugar Creek Plant for failing to manage how and when workers entered the large round pipe, and other violations of federal safety guidelines for confined spaces in construction.