Two people were killed and two were injured when a Kinder Morgan natural gas pipeline exploded in Illinois on Tuesday, the company has confirmed. The deaths and explosion come at a time when the pipeline firm is battling to build its Trans Mountain expansion project in Western Canada in the face of fierce opposition. On the morning of Dec. 5, 59-year-old Rory Miller and his son, 30-year-old Ryan Miller were killed when a buried gas pipeline operated by the Texas-based multinational exploded in Lee County, Ill. about 150 kilometres west of Chicago, according to the Associated Press.

As of the evening of Dec. 6, 20-year-old Michael Koster is in critical condition and 20-year-old Kyler Acklund was treated for injuries and released from the hospital. Local resident Colleen Clausen described "100-foot" flames to WTVO / WQRF TV local news division Eyewitness News. "We weren't sure if a bomb went off," Clausen is quoted as saying. The Lee County Sheriff’s Office said two tractors got stuck, and one hit the pipeline, a Dow Jones report stated. It said the two killed were found dead at the scene and area residents rushed the other two injured to hospital. Lexey Long, a spokeswoman for Kinder Morgan, told National Observer the impacted pipeline has been “isolated and the area was secured.”

The company is working with local, state and federal agencies on response efforts, has notified regulatory agencies and is working with customers on impacts to service, she said. “Our thoughts and prayers are with the families of the injured and deceased,” said Long. Mandatory call wasn't placed, Kinder Morgan says In its statement, Kinder Morgan said a mandatory call wasn’t placed alerting the company to digging in the field. “Unfortunately, a required one call notification was not provided to the company prior to the work being performed,” said Long. Matt Krogh, a campaign director for environmental group Stand.earth, said in an interview that he agreed that people should call a company before digging or doing work around an active gas line. But he added that the issue also emphasizes the risk of gas pipelines to communities. “Certainly having a gas pipeline on your property is something that people should be very aware of, and probably worried about,” said Krogh, who specializes in campaigns against what the Stand.earth describes as "extreme oil" production and extraction. “It’s a one-time tragedy, but we keep seeing pipelines explode, and leak.”

Krogh said the the situation “serves as a sobering reminder” of the fact that thousands of people are exposed to pipelines in the United States and Canada. “One way or the other, what you have is a Texas-based company that is running a series of risky propositions in the form of pipelines,” he said. Editor's note: this story was updated at 5:30 p.m. EST on Dec. 6 to include new details from the Lee County Sheriff’s Office and an interview with Matt Krogh.