Even more people would likely die if the 1917 Halifax Explosion occurred today

Highrises coated in glass crowd the skyline of modern-day Halifax, a much different scene than 100 years ago when timber frames and simple masonry made up the cityscapenear the city's waterfront.

On the cool, clear morning ofDec. 6, 1917, swaths of the city were demolished in an instant by the largest human-caused explosion before the atomic bomb.

With about 2,000 dead, the Halifax Explosion remains one of deadliest disasters in Canadian history. But what would happen if asimilar explosion occurred inHalifax today?

The answer, according to John Newhook, is the death toll would likely be even worse.

"The density of people downtown now is much larger," said Newhook, a professor of civil engineering at Dalhousie University.

"So even if the zone of damage will still contain to approximately the same area as it was 100 years ago, imagine how many more people are living and working in that area now."

Between 60,000 and 65,000 people livedin Halifax and Dartmouth in 1917when the Belgian relief ship Imo collided in Halifax harbour with the Mont-Blanc, the French munitions ship that caught fire and caused the Halifax Explosion.

Today, more than 315,000 people livein the urban area around Halifax harbour, according to Statistics Canada.

Newhook said given the number of casualties that would result from a modern-day blast of the same magnitude, it would be a "massive challenge" for first responders and emergency crews.

"Who has an emergency management plan conceiving that much injury and fatality in such a short period of time?" said Newhook.

• INTERACTIVE | Experience the Halifax Explosion in 360 video

The Halifax Emergency Management Office does.

Casualties from a Halifax Explosion-like event would be inevitable, but there are tools that weren't availablein 1917, according to Barry Manuel, the agency's Halifax co-ordinator.

One of those is a radio system that allows police officers, firefighters and paramedics to co-ordinate. Modern information systems would also tell officials that hugeamounts of explosives were aboard one of the ships before it blew up.

The Halifax Explosion didn't just kill a lot of people. It's estimated one in 50 survivors wasblinded by flying glass and debris, the largest mass blinding in Canadian history.

In the century since, numerous towering buildings made of glass have been built in Halifax.

The height of those buildings might absorb some of the blast strength, said Newhook, but it's not clear how much since engineers don't usually consider the power of such an explosion in modern construction.

"Some of our buildings would provide that shelter,but they may not be something that's as safe as you think," said Newhook. "The glass, the brickwork, the other things that's on these buildings could become just as dangerous or more dangerous than if the building collapsed."

Then there's the evacuation. Anyone who hasever tried to make it off the Halifax peninsula at the height of rush hour or after a major sporting event can tell you it's a slow slog.

On Dec. 6, 1917, the Mont-Blanc exploded just 19 minutes and 35 seconds after the collision with the Imo.

"There is no way that we evacuate downtown that quickly," said Newhook. "It may turn out that there's a lot of potential for people to get injured because they're in their cars or they're on the streets trying to get away from the blast zone but we can't efficiently get them away."

Manuel said a blast the size of the Halifax Explosion would certainly compromise the integrity of the Macdonald and MacKay bridges, two of the main routes off the peninsula.

"You couldn't put people across the bridge until they were checked for integrity," he said. "I'm assuming that with that so close to the north bridge that in that scenario the bridge would be compromised."

Something else to consider isall the combustibles now on the peninsula, such as naturalgas lines.A giant blast in the harbour could trigger secondary explosions in downtown Halifax, Newhook said, and lead to a fire even worse than what followed the 1917 explosion.

"That secondary wave, if you will could be much worse than what happened 100 years ago," he said.

In recent years, local emergency officials have dealt with natural disasters likeHurricane Juan in 2003 and the 2004 nor'easter blizzardWhite Juan. But they don't hold a candle to the devastation wrought that day in December 1917.

"Those things aren't even in the frame of reference of the kind of air-pressure damage that's going to be done by an explosion like that," said Newhook.