Melanson said he has seen explosions like this on YouTube at oil refineries around the world, but never seen anything like this in Saint John.
The Irving Oil Refinery is a Canadian oil refinery located in Saint John, New Brunswick.
Nearby resident Bob McVicar posted on Facebook saying that it felt like a "bed-shaking explosion".
"As an update on our Saint John refinery incident this morning, we now understand that all employees and contractors working on site have been safely accounted for".
"My whole house shook", she said.
Geoffrey Downey, spokesperson with the New Brunswick Emergency Measures Organization, said there were only "couple minor injuries at this point, but nothing serious".
The massive plant can refine as much as 320,000 barrels a day of gasoline, diesel heating oil, jet fuel and other petroleum products.
According to the CBC, many residents reported an explosion and fire at the Irving oil refinery in Saint John on Monday morning.
"There was thick, pitch black smoke mixed with white smoke", said Guimond.
Meanwhile, Saint John Police are asking the public to avoid the area.
He noticed black smoke coming from the refinery and when he went to get a closer look, noticed huge flames shooting 30 metres high into the sky.
"I heard a rumbling, roaring sound", Guimond said. Nearby streets have also been closed.
He made a decision to drive by the refinery, and said he was nearby when he felt the vibrations of what he assumed must be a second explosion.
In an earlier tweet, the company characterised the incident as a major one.
Irving says on Twitter that the company is "actively assessing the situation" and will share more information when it becomes available.