In December of 2013, an engineer fell asleep while driving a Metro-North train in the Bronx. It derailed, killing 4 people.
The NTSB released a report on Wednesday with safety recommendations. Among those recommendations is that railroads should routinely screen employees who perform "safety-sensitive" functions for sleep disorders.
NTSB Chairman Christopher Hart says they've made the recommendation to regulators of all transportation industries. He says, for example, it’s been helpful for the trucking industry.