The demand for better and faster cell phone service comes with a hidden cost. This joint investigation by FRONTLINE and ProPublica has found that the independent contractors who are building and servicing America's cellular infrastructure are 10 times more likely than an average construction worker to die on the job. Complex layers of subcontracting insulate the carriers against liability, despite the fact that they set the aggressive schedule that can force subcontractors to cut corners in order to meet deadlines.