The Halifax harbour explosion of 1917 remains one of the most devastating disasters in Canadian history. Nearly 2,000 people died when a ship loaded with explosives bumped into another vessel and detonated.

Ninety-nine years later, rare archival video of the day is being publically displayed at the Army Museum Halifax Citadel.

The black-and-white images are some of the only moving depictions of Halifax in the hours after the blast. Fires can be seen burning across town, windows are blown out and countless buildings are reduced to rubble. The scenes were shot by W. G. MacLaughlan, a photographer who had a studio in town.

“At the time, the population was a little more than 50,000 people, so half of this city was directly and devastatingly affected by the explosion,” Ken Hynes, a curator at the museum, told CTV Atlantic.

The explosion unfolded on Dec. 6, 1917 when a French ship filled with explosives equivalent to 5,000 tons of TNT accidentally hit a ship from Norway in the waters off Halifax. The collision sparked a massive shockwave that rocked Halifax, levelled entire neighbourhoods and altered the course of Atlantic Canadian history.

Nearly a century later, historians are still learning more about the catastrophe. A researcher who extrapolated figures from the explosion says modern-day Halifax would be hit even harder by the blast.

“If the Halifax explosion were to occur today, we would immediately have 9,600 dead, over 43,000 wounded and 120,000 without adequate shelter,” said historian and author John Boileau.

Historians have spent decades poring over materials from the days after the blast in an effort to learn more about how the community responded to the crisis.

“It can be as little as somebody writing a postcard or a letter saying, ‘I was in Halifax and I saw the devastation,’” said historian Blair Beed.

For documentary filmmaker John Versteege, the harbour explosion was so fascinating that he compiled hours of never-before-seen footage and interviews with survivors to piece together what happened. He produced the film in “Thunder in the Sky,” a 97-minute documentary released in 1993 on the 75th anniversary of the disaster.

“Big pictures are made out of millions of small events,” Versteege said.

The priceless moving pictures are among a trove of other artifacts on display at the Halifax museum, including a watchman’s clock recovered from beneath a dock in the harbour. Its face is permanently frozen at 9:04 a.m. -- the same minute the explosives went off.

With files from CTV Atlantic