The company that owns the refinery confirmed on Twitter that a "major incident" occurred there.
The Irving Oil Refinery is a Canadian oil refinery located in Saint John, New Brunswick.
A massive refinery blast shook Saint John on Monday, sending flames and black smoke into the sky but causing only minor injuries, leaving officials relieved it wasn't far worse.
He said there had been a problem with the refinery's diesel treating unit, which removes sulphur from diesel fuel, but it wasn't yet clear exactly what caused the malfunction.
There were as many as 3,000 workers on the refinery Monday _ but most of the facility was shut down for major maintenance, and almost all of the workers were contractors working on the turn-around.
Tom Kloza, global head of energy analysis at Oil Price Information Service told CNBC 'We probably import more gasoline from that single refinery than any other single refinery around the world, ' he said.
Nick Hynes says he was not long off of the night shift when the blast occurred. Five years ago, the New England Petroleum Council said 70 percent of Maine's gasoline comes from the Saint John refinery, although it also can receive fuel from refineries in New Jersey and Philadelphia.
Irving's Saint John refinery is the largest in Canada.
Already know everything about the Pixel 3? Google thinks you don’t
Now, what exactly Google has in mind we will get to know in a few hours when the company officially unveils the device. The Google Pixel 3 XL will retain the Active Edge gesture that it had introduced with the Pixel 2 XL .
"We're sitting here and watching it burn right now".
The refinery is near several residential neighborhoods on Saint John's east side.
They looked outside the window and saw black smoke and flames exceeding the height of the stacks at the refinery.
Some roads near the refinery remained closed Monday afternoon, but no evacuations were ordered for residents living nearby.
"I heard a rumbling, roaring sound", Guimond said.
We will update as more information becomes available.
He made a decision to drive by the refinery and said he was nearby when he felt the vibrations of what he assumed must have been a second explosion.