Organizers were expecting 30 million people to tour Man and his World – but by the time the doors closed on Expo '67, attendance was almost double that.

Fifty years after it opened, a new documentary celebrates the people who made it possible.

The story the filmmakers tell in Expo 67: Mission Impossible reveals what went on behind the scenes at the international exhibition.

The enormity of the task was all the more impressive considering it was completed in only three and a half years - something that should have taken 12.

A metro tunnel, highways and bridges were all constructed at the same time to accommodate the crowds.

Teams toiled to build not just the pavilions to welcome the world to Montreal, but to create the site itself in the middle of the St. Lawrence River.

The theme - Man and his World – was to build bridges between people.

All photos: Library and Archives Canada

Then-mayor Jean Drapeau is credited as the force behind expo, but the filmmakers say those behind the scenes were the real heroes.

“It was the sum of all their good intentions and the culture mix,” said co-producer Eric Ruel.

Two of those people - Philippe de Gaspe Beaubien and Yves Jasmin - consider the enormous crowds at Expo their biggest legacy.

“That it was a success, and it was an impressive success,” said Jasmin, who served at Expo ‘67’s communications director.

Philippe de Gaspe Beaubien

For de Gaspe Beaubien, who served as the chief operating offer, Expo came at just the right time.

“I could see that the country needed that, the province needed that, the young people needed that,” he said.

It represented a world of possibilities on exhibit for all to see, as 200,000 people a day passed through the turnstiles. In all, 55 million people eventually toured the site.

Montreal's future mayor Denis Coderre was only four when Expo opened - too young to attend but proud of the legacy.

“You have a lot of people who thought it was impossible and that's what Montreal is all about: everything is possible,” he said.