While at one point Montreal’s Sun Life building was among the tallest in Canada, it no longer towers over the city’s skyline. Still, after 100 years, the structure is still a standout.

Earlier this week, the building celebrated its birthday with a replica cake, one that was well-earned after a century of service.

Built between 1914 and 1918, the original building was only six stories high. By 1923, Sun Life – eastern Canada’s first life insurance company – was doing so well that a new wing was added. Five years later, a third phase began, one which would make it one of the tallest buildings in the city.

That third phase would make the building home to 10,000 employees, a shooting range and bowling alleys, but with World War II looming, a massive vault with a 30-tonne door was added. Inside was kept $5 billion British foreign securities, a secret fortune transported across the Atlantic in crates marked “fish.”

While legend had it that the fortune was in gold bars, Sun Life Quebec President Robert Dumas said it was all paper assets, secretly stored in filing cabinets until the end of the war.

In 1978, after the passage of Bill 101, Sun Life moved its headquarters to Toronto. About 800 employees relocated, but the building still remains.

“The other day, I was coming to the building on a different street and from a totally different angle and it was just as beautiful,” said Dumas.