Randall Andres and Devin Smith are too young to remember what they were doing on Sept. 11, 2001.

Yet, the youthful firefighters were out Wednesday at a Kelowna stair-climbing event to commemorate the 18th anniversary of the 9/11 terror attacks.

"I was five when it happened, so I don't remember it at all," said Andres, 23, who is a member of the Big White Fire Department.

"But as a firefighter myself, I know that 343 firefighters lost their lives that day and that hits me hard."

Devin Smith, 20, was only two years old when two jets were crashed into the north and south towers of the World Trade Centre complex in New York, causing both of the 110-storey skyscrapers to collapse.

"I don't remember a thing of that day, but I'm here today to do my part," said Smith, a member of Peachland Fire and Rescue.

Smith and Andres were among 20 firefighters from departments throughout the Okanagan who showed up in full firefighting gear Wednesday for the second annual 9/11 Stair Climb at Kelowna's tallest office building.

"I'm wearing my big jacket, pants, boots, helmet, air pack and balaclava," said Andres.

Kelowna doesn't have a 110-storey building to mirror the height of the fallen World Trade towers.

So, the 18-storey Landmark 6 building was chosen.

Firefighters ascended the stairs from the lobby to floor 17 a total of seven times for a cumulative 119 storeys.

The climbing started at 8:46 a.m., the time the first plane slammed into the World Trade's north tower.

The Kelowna event wasn't a race or a competition.

Firefighters went at their own pace as an act of remembrance and respect.

Each of the participating firefighters also donated a minimum of $20 to the Kelowna Professional Firefighters Charitable Society.

The money will be forwarded to Wounded Warriors Canada to support first responders affected by post-traumatic stress disorder (PTSD).

"It's important to honour not just the 343 firefighters who lost their lives in 9/11, but the 60 other first responders (police and port authority) and the almost 3,000 other who were killed and the 6,000 injured," said Kelowna Fire Department training officer Glenn Paley, who organized the local stair-climb.

"There's also been a further 1,400 first responder deaths in the years since of cancers and lung disease caused by the conditions endured on 9/11 and many of their families are still fighting for benefits."

Next year, the 9/11 Stair Climb will be held on a weekend, so more firefighters can participate.