Several Canadian cities are marking the 10th anniversary of the Sept. 11 terrorist attacks, including the tiny Newfoundland community that sheltered and offered kindness to stranded travellers the day of the tragedy.

A memorial service is being held in Gander, N.L., the small town that became a temporary home for thousands of passengers on diverted international flights when the U.S. closed its airspace after the attacks on the World Trade Center and the Pentagon.

Residents of Gander and nearby communities, Gambo and Lewisporte, welcomed strangers into their homes, volunteered at makeshift shelters in town and donated food to the nearly 6,600 unexpected visitors for five days.

Hundreds of residents, dignitaries and visitors gathered in the local hockey rink that served as a giant walk-in fridge for food donated to the stranded travelers when the U.S. shut down its air space to all but military aircraft for the first time in history.

U.S. Ambassador David Jacobson along with Newfoundland and Labrador Premier Kathy Dunderdale attended the memorial service.

Jacobson said the unselfishness of the people of Gander, and of all Canadians, needs to be remembered.

He also said it is now a time to commemorate the bonds shared between Canadians and Americans.

"It's time to remind the world of our gratitude," he said. "It's time to celebrate the spirit of resilience, the spirit of defiance."

Gander Mayor Claude Elliott gave an emotional address, saying that the communities of Gander and neighbouring towns represented the exact opposite of the hate the terrorist acts reflected.

"Good can outfight evil any time," Elliott told the gathered crowd of residents and visitors on Sunday. "Human kindness and love and compassion are what our world is lacking today, we need more of it."

Children from the Gander Academy Grade 2 choir sang a song that included the lines "The future can be brighter, it's up to me and you."

Two steel beams from the World Trade Center, donated to the town of Gander, were unveiled at the ceremony. The rusting and slightly twisted beams, which were blessed during the ceremony, will be placed in the Gander Aviation Museum.

Reporting from Gander, CTV's Todd Battis called the atmosphere "almost festive" on Sunday as American visitors rekindled friendships with the residents who sheltered them 10 years ago.

Gander volunteer Beulah Cooper, 70, took three stranded passengers into her home and offered showers to several others.

Cooper, who also helped at a makeshift shelter in the local Royal Canadian Legion hall, said that helping is just something that comes naturally to Newfoundlanders.

"For the best part, we are very giving people and we tend to help each other without thinking twice," Cooper told The Canadian Press on Sunday.

Other communities in Canada's east coast, including Halifax and Moncton, N.B., also had planes crowd their runways when about 200 flights were diverted to Canadian airports.

In Halifax, 40 aircraft landed, releasing a combined 8,000 passengers on the city.

U.S. consul-general Anton Smith was in Halifax on Sunday to present a plaque to airport managers to thank employees and local residents for their help.

In Ottawa an open-air concert, attended by several hundred visitors, began at precisely 8:46 a.m., the moment the first plane hit the World Trade Center.

Jean Chretien, who was prime minister at the time of the attacks, also attended the concert on Sunday.

He recalled how 100,000 Canadians turned out on Parliament Hill to express their solidarity with Americans in the days immediately following 9-11.

"I remember too, the Friday, rather than have a service in a church, we decided that it was to be open, that we were not to go in hiding and we had 100,000 people on the Hill," he said, adding that the greatest moment was the moving three minutes of silence that day.

U.S. President Barack Obama thanked Canadians for their help in a letter sent to Prime Minister Stephen Harper last week.

He paid special tribute to the residents of Gander.

"We remember with gratitude and affection how the people of Canada offered us the comfort of friendship and extraordinary assistance that day and in the following days by opening their airports, homes and hearts to us," Obama wrote.

Prime Minister Stephen Harper is in New York for anniversary events at Ground Zero. Harper formally designated Sept. 11 as a national day of service to pay tribute to both the victims and the Canadian communities who helped stranded travelers.

There are also events planned for Ottawa, Edmonton, Toronto and Calgary.

Canada remembers:

Memorial services were held in other communities across Canada as well on Sunday.

In Montreal, Quebec Premier Jean Charest unveiled a plaque commemorating the attacks.

"We need to look ahead now, I think, with a renewed determination for tolerance and peace and openness if we want to avoid this kind of thing happening again," he said at the city's centre for international trade.

A tribute at Nathan Phillips Square in front of Toronto's City Hall included a march-past by Toronto police, fire and EMS honour guard units along with bagpipes and drummers from the city's paramedics.

A moment of silence was observed and the "Last Alarm" fire bell was repeatedly struck in honour of fallen first responders.

With files from The Canadian Press