Canada has been out of active combat operations in Afghanistan for more than two years, but soldiers are still dying.

Over the past two weeks, four more Canadian soldiers died, but not at the hands of the Taliban ... it appears that they committed suicide.

Over the course of active combat, the Canadian Forces lost 158 soldiers, with more than 2,000 injured in Afghanistan. Twenty died, and another 100 plus were injured in the Balkans.

But those numbers don't include suicides. They don't include soldiers who were injured, mentally, from the trauma they endured, while serving their country. They don't include the soldiers who remain broken years later, many still struggling with post-traumatic stress disorder.

The Canadian military is investigating the deaths of Master Corporal Sylvain Lelievre, Warrant Officer Michael McNeil, Master Corporal William Elliott and Master Bombardier Travis Halmrast.

News of the recent spate of suspected suicides hit Senator Roméo Dallaire particularly hard.

The Senator, of course, suffered ... and continues to suffer ... from the horrors he witnessed during a long and distinguished military career.

The retired lieutenant-general was the force commander of the UN's Assistance Mission in Rwanda, leading up to and during the 1994 genocide in which at least half a million people were killed.

Next April will mark 20 years since the genocide began, an anniversary that is also weighing heavily on Senator Dallaire.

Exhausted from being unable to sleep, the Senator nodded off at the wheel of his car last week on Parliament Hill.

Michael talks with Senator Dallaire, from his office in Ottawa.