TWO SAS soldiers have gone on trial by court martial over the deaths of three reservists, one of which was from Trowbridge, on a 16-mile march in the Brecon Beacons.

The men, known only as 1A and 1B, both deny “negligently performing a duty” by failing to take reasonable care for the health and safety of candidates taking part in the exercises.

Lance Corporals Craig Roberts and Edward Maher were pronounced dead on the Welsh mountain range after suffering heatstroke on July 13, 2013.

Corporal James Dunsby, of Trowbridge, died at Birmingham’s Queen Elizabeth Hospital from multiple organ failure more than two weeks later.

1A and 1B, whose identities are protected by an anonymity order, went on trial at the Court Martial Centre in Bulford, Wiltshire, on Monday.

1A was a captain and the training officer in charge of the march, while 1B was a warrant officer and the chief instructor on the exercise.

Prosecuting, Louis Mably QC told the five-person board: “In those respective roles, they were the safety officers for the exercise.

“The charge against the defendants is that they were negligent in their duty to plan and conduct the exercise safely in relation to the well-known risk of heat illness.

“The risk to the candidates wasn’t properly appreciated or assessed and in this regard there was a negligent failure with planning and preparation.

“Two reservist candidates collapsed on the road from heat illness and died where they fell.

“A third reservist who also collapsed on the road later died in hospital.

“There were also a number of non-fatal heat illness casualties.”

Mr Mably told the board that the risk of heat illness was well known and “the defendants ought to have taken proper attention” to it.

“It is of course the case that with an arduous endurance exercise the risk of heat illness cannot be eliminated completely,” he said.

“But the risk did need to be properly evaluated by the defendants.

“They needed to prepare and plan for it and on the ground, they needed to be ready to act in a dynamic way if the risk arose.

“When things began to unfold on the Brecon Beacons, they were in no position to respond with any real effect.

“What the prosecution say is that this was negligent.”

The court heard 1B filled out the risk assessment form for the exercise and it was signed by 1A in June 2013, the month before it took place.

Thirty-seven reservists and 41 regular troops took part in the exercise. The court martial continues.