NORWALK - Certain employees at Metro-North could soon be screened for sleep apnea.

The policy change is the result of the deadly derailment last year in the Bronx where four people died. A federal report found the engineer suffered from sleep apnea but was undiagnosed.

Metro-North is currently talking with its unions about setting up a program to combat the disorder in the hopes of preventing future problems.

Sleep apnea is a disorder that causes fatigue because sufferers repeatedly wake up throughout the night.