This article was originally published by Global News and appears here as part of the Price of Oil collaboration.

Imperial Oil Ltd. will not be charged for a Feb. 23, 2017, incident that saw huge flames shooting from its Sarnia refinery, which residents described as being “absolutely anxiety-inducing.”

Video of the flames, captured from the Michigan side of the St. Clair River, went viral on social media.

“It looked like Canada was on fire,” Megan Hayden, who filmed from her cell phone, said at the time. “It almost sounded like the engine of a freighter.”

According to Ministry of the Environment documents, the heavy flaring at Imperial Oil occurred due to “unstable operating conditions” and a loss of “air supply resulting in the shut-down of several processing units within the refinery.” Imperial Oil reported the event to the ministry’s Spills Action Centre, notified the surrounded community, and monitored the flaring.

“Flaring is used in industrial facilities, like petroleum refineries, to burn off unwanted or excess flammable gases,” said Gary Wheeler, ministry spokesperson.

Cell phone video captures extreme flaring at the Imperial Oil refinery in Sarnia, ON on Feb 23, 2017.

Yet the ministry would not provide a detailed answer as to why charges were not laid.

Nor would the ministry address whether the incident impacted the local community, which can also constitute a violation of Ontario’s Environmental Protection Act.

Under the Act, discharging a contaminant which causes an “adverse effect,” including impacting “the health of any person” or “loss of enjoyment of normal use of property,” can be an offence. Penalties vary from $25,000 to $10 million, depending on whether it is a repeat offence and the severity of the incident.

Witnesses to the Feb. 23 event reported being in a “panic.” Local councillor Brian White, who was not interviewed by the Environment Ministry for its investigation, said, “people were struck with the fear that this place was going to blow up.”

Nikki Jean, who lives in neighbouring Aamjiwnaang First Nation said, “my daughter could feel (the) ground shaking and the windows … shaking.”

Jean said, despite it being the middle of winter, they turned off the heat in the house, concerned about what they were breathing in.

“Our immediate reaction is, turn the air off, close the windows, stay in your home. You can’t go out and enjoy yourself.”

The ministry’s investigation, which took more than year, was initiated after a joint application by Aamjiwnaang member Vanessa Gray and the environmental law charity EcoJustice. It also came in the wake of a Global News documentary that exposed the troubling trend of industrial leaks in spills in the Sarnia area, known to many as “Chemical Valley.”

“By refusing to prosecute Imperial Oil, the ministry is signalling that the minister’s promise to police industry and enforce existing environmental laws is an empty one,” said Elaine MacDonald, an environmental engineer with EcoJustice.

Ontario’s Environment Minister Rod Phillips cancelled a scheduled interview for this story with Global News.

Imperial Oil also declined to comment.