 and from listeners like you who donate to this NPR station. This is Morning Edition from NPR News. I'm Michelle Martin. And I'm Ian Martinez. All right, we turn now to a dangerous problem for construction workers, specifically those who work in trenches, these deep ditches you see along the highway at large construction sites and new home builds. Now, without the proper systems in place, those trenches can collapse in an instant, burying the workers alive in a dense slurry of mud and water.