A Calgary reservist accused of manslaughter in the death of one of his fellow soldiers in 2010 has pleaded not guilty to all of the charges against him.

Major Darryl Watts faces six charges, including manslaughter in the death of Corporal Josh Baker.

He is also charged with two counts of negligent performance of a military duty, one count of unlawfully causing bodily harm and two counts of breach of duty.

Baker was killed and four others were hurt  in 2010 after a Claymore mine on a training range in Afghanistan exploded, sending 700 steel balls at the platoon.

Baker was just 24 years old when he was killed.

Watts was in charge on the day of the incident.

Watts' defence lawyer, Balfour Der, says his client did nothing wrong before the device exploded.

Der says the prosecution has the situation wrong by accusing Watts of manslaughter and then arguing he was negligent.

The trial is expected to take five weeks at the Mewata Armoury and will be overseen by a military judge and five officers.

If Watts is found guilty, he could face anything from jail time, fines, or dismissal from the military.

In his civilian life, Watts is a senior firefighter for the Calgary Fire Department.

His deputy chief Ken Uzeloc attended the hearing to show his support. "Darryl has always been an exemplary person in the fire department. Very caring, mentoring to junior members and a proven leader within our department."

The prosecution in the case says the unsafe conduct on the range that day was unacceptable and that Watts was ultimately responsible as he was the platoon leader.

Watts' lawyer Balfour Der says his client was not running the weapons drills that day so he should not be held responsible for the tragedy.

"Manslaughter is an overcharge. I think all of the charges are overcharges, because I don't think the man did anything wrong," said Der.

Two other Canadian Forces personnel were charged following the accident.

Warrant Officer Paul Ravensdale, who was the safety officer at the firing range, faces identical charges to Watts.

Last September, Maj. Christopher Lunney pleaded guilty to negligent performance of duty while four other charges were dropped. He was demoted to captain and received a severe reprimand.