Tuesday afternoon, Quebec Senator Roméo Dallaire crashed his car on Parliament Hill after falling asleep at the wheel.

"On my way to work this morning, I fell asleep at the wheel and crashed into the barrier near the East Block with my car. I am very thankful that nobody was injured or worse by my not being more attentive to the level of fatigue that I have been experiencing," Dallaire told the Senate on Tuesday after the incident.

Dallaire says the accident was caused by a lack of sleep triggered by his traumatic memories of the Rwandan genocide and the recent apparent suicides of as many as four former Canadian soldiers suffering from post-traumatic stress disorder.

Dallaire describes PTSD as “the injury that starts when the shooting stops.”

Those deaths have weighed heavily on Dallaire, who went public about his own PTSD in 2000. He told Sunday Edition host Michael Enright that he worries Canada doesn’t have the resources to meet the current or future medical needs of soldiers with PTSD.

The 20th anniversary of the Rwandan genocide has also been preying on Dallaire’s mind. The retired lieutenant-general was the force commander of the UN's Assistance Mission to Rwanda leading up to, and during, the 1994 genocide.

Dallaire says he realized only recently that he will live with PTSD the rest of his life. The most banal incident can trigger a flashback for Dallaire — like the time his one-year-old granddaughter cried after hurting herself.

While everyone else in the room was reacting to her tears, Dallaire says he was "nearly paralyzed” in his chair. In his mind he saw the hundreds of children he had seen in Rwanda, “In all kinds of states of destruction and savagely abused.” 

It reached a point where he was afraid to pick up his granddaughter, worried that if she cried again he might drop her. “These things can come at you from some pretty horrific angles,” he says.