Robert Higgins and Kelvin Mattocks went to work on a fall day in Boston, just like any other day. On that day – Oct. 21, 2016 – the approximately 12-foot deep trench in which they were working collapsed, trapping them in soil up to their waists. The trench collapse caused an adjacent fire hydrant supply line to snap. It quickly filled the trench with water, drowning the men within a matter of seconds in a terrifying, watery grave. Despite the desperate efforts of their coworkers, the men died at the scene.