On Aug. 9, 1974, Canada saw its greatest loss of life when a peacekeeping mission where nine Canadian peacekeepers were killed.

Their plane was shot down by Syrian missiles during a resupply mission in the Middle East.

Nearly 40 years later, in 2008, National Peacekeepers' Day was established.

On Tuesday night, a parade was held in Waterloo Region to recognize those who fought and continue to fight to keep international peace.

“I’ve always said that it's never an easy tour or easy mission until you're back on Canadian soil because you never know when the last day's going to be,” said Sgt. John Champion, 31 combat engineer regiment.

Sgt. Champion served in Kosovo twenty-two years ago.

Nearly 40,000 Canadian peacekeepers served to combat the violent unrest in the Balkans and help to maintain peace, security and stability.

Sgt. Champion served as a police officer as part of the United Nations mission, including in the homicide unit.

He says it's a challenging job playing referee through so much turmoil.

"With the UN, you're usually going into a country that's very different than your own, so it's a bit of a culture shock when you first get there, and you're trying to operate under rules of law that the locals don't necessarily accept,” said Champion.

Wreaths are laid by the cenotaph to remember those who served, including those who made the ultimate sacrifice.

“I think the butterflies definitely went in the stomach the first time the light-armoured vehicle ramp went down. You're stepping your foot into that sand for the first time, and it's no longer training, so if something goes wrong, it could be the end of it,” said warrant officer Tim Nightingale with the 31 combat engineer regiment.

Nightingale served in Afghanistan looking for improvised explosive devices and roadside bombs.

He would later go to Lebanon as part of a training mission for the local military.

Nightingale said he hopes the day can be a moment to recognize the value of peace and those who keep it.

Since 1948, more than 125,000 Canadian peacekeepers have participated in international efforts.

Canadian Prime Minister Justin Trudeau issued a statement on Tuesday honouring all Canadians who have served, commending their courage, perseverance and compassion.