<p>The Australian Transport Safety Bureau will investigate the circumstances surrounding the death of two rail workers struck by an empty coal train in the Hunter Valley early this morning (Monday, July 16).</p> <p>The signal technicians, employed by the Australian Rail Track Corporation, were killed instantly when hit by the northbound train at Singleton station in New South Wales about 5.50 am.</p> <p>Police said both workers were wearing brightly-coloured vests, in accordance with standard safety policy.</p> <p>The Rail, Tram and Bus Union said it was the first fatality on the track for four years.</p> <p>Rail services were disrupted this morning as police, WorkCover and the ATSB conduct an investigation. </p> <p>The workers are yet to be formally identified. </p> <br />