On a cold night in Otterburne, Manitoba, near the Canada-US border, a giant fireball erupted from a TransCanada pipeline carrying natural gas, ejecting debris 100 meters from the site and blasting a crater as long as two city buses.

Eveline Wiebe, who saw the flames from her farmhouse window, wondered if it was the apocalypse. "Wow, is it the end of the world or something?" she told the Winnipeg Free Press at the time of the incident in January 2014.

It took 12 hours for the blaze to burn out, and in the meantime, five nearby homes were evacuated and the highway was closed to traffic.

As is the case across much of North America, the pipeline ran through a sparsely populated area, with the nearest town holding 120 residents. No injuries were reported.

But that hasn't stopped two whistleblowers who worked at TransCanada from worrying that a dangerous explosion could one day happen in someone's backyard.

Otterburne pipeline fire/YouTube

The Otterburne fireball was one of 74 reported fires and explosions — 9 explosions and 65 fires — at TransCanada-owned facilities in Canada since 2008. TransCanada, the same company that wants to build the Keystone XL and Energy East pipelines, has tallied more than 300 "reportable incidents," including ruptures, leaks, fires, explosions, serious injuries, and one death, at its facilities since 2008 — a number that far outstrips any other Canadian pipeline company in that time period.

The federal regulator, the National Energy Board (NEB), told VICE News the numbers are higher for TransCanada because they own almost 60 percent of the pipeline in Canada.

For those two former TransCanada workers, though, those numbers are a reflection of rampant safety problems they say they witnessed when they worked at the company, including poor inspection practices, cracks in pipelines, and inexperienced workers. Both were let go after they repeatedly complained to the company about those issues. They say they were never told why they were fired. They reported their concerns to the NEB and also shared their allegations with VICE News.

On Friday, the NEB released an investigation into the allegations of one of the whistleblowers — more than a year after he formally reported them in September 2014. The NEB investigation found that six of his 16 allegations were partially substantiated, although the federal regulator said none of these were an immediate threat to the public. The regulator found TransCanada had addressed the complaints and there was no reason to take action against the company.

But the two whistleblowers VICE News spoke to allege TransCanada is not following safety regulations. And they accuse the NEB of not doing enough to ensure TransCanada and other companies follow safety standards.

The NEB has issued 30 safety orders to TransCanada, conducted 301 "compliance-related activities," and audited the company's management system between 2012 and 2014.

Regulator spokesperson Darin Barter told VICE News the NEB takes all allegations of regulatory non-compliance seriously. "The NEB will not hesitate to take immediate enforcement action if a non-compliance is determined to be an immediate threat to the safety of workers, the public or the environment," Barter wrote in an email.

TransCanada says it shares the regulator's focus on safety for the public, its employees, and the environment. "We want to stress that any time an issue is brought to our attention, whether by an employee, a contractor, inspectors who ensure quality control for our pipeline, or a member of the public, we act appropriately, proactively and of our own accord," company spokesperson Davis Sheremata said in an email.

"We use all incidents as learning opportunities to strive even more rigorously toward our goal of zero incidents," he added, addressing the Otterburne incident specifically.

The Otterburne fireball ignited on January 25, 2014. It wasn't until July of that year that the Transportation Safety Board determined the cause of the fire was a pre-existing crack that went unnoticed due to lack of welding regulations when the pipe was welded, 50 years earlier. It's likely that the freezing temperatures in the coldest winter since 1898 contracted the pipe, the TSB said, and when combined with weakened soil support and pipeline inactivity, the crack ruptured and the gas ignited.

Officially the NEB classified the Otterburne incident as a "fire" and not an explosion, though the ignition of gas ejected debris and left a gash in the earth.

"Based on standard industry practice at the time of construction, the weld at the failure location had likely been inspected only by visual means," the TSB report said.

While regulations governing welding inspections exist now, one of the whistleblowers, who worked as a TransCanada engineer, told VICE News the company was not following those regulations when he worked there.

Evan Vokes blew the whistle on the company on May 1, 2012, and was fired on May 8. CBC reported his allegations in October 2012. Vokes alleged pipeline companies including TransCanada have poor welding practices and shoddy inspection, resulting in thousands of cracks in pipelines and "time bombs all over the place."

"And then Otterburn happens and they say, Oh don't worry, that was how we did it 50 years ago," he said. "Well how about this here? We're doing it right now. That's my whole point. It's pretty scary."

"There is no inspection really. The only inspection is, 'Get that bitch in the ditch,'" Vokes said, quoting a pipeline worker expression. "And [TransCanada] can say whatever they want, but that's what they've done."

TransCanada says its current welding and testing processes are designed to locate small cracks like the one that led to the Otterburne incident, and it says it is continually testing new pipeline-inspection technologies.

However, as VICE's Motherboard reported in July, 70 percent of TransCanada's rural pipelines are small-diameter pipes, which are too small to be inspected by defect-inspecting robots called "smart pigs." As of 2014, only 26 percent of those small-diameter pipes had been examined.

In June 2013, Vokes testified before Canada's Standing Senate Committee on Energy, the Environment and Natural Resources.

"We have been told that the pipelines have a safety record of 99.9 percent," Senator Betty Unger said then. "You paint a very bleak picture of the pipeline industry in Canada, and probably by extension, into the United States. How do you rationalize these two very diverse points of view?"

"It is amazing," Vokes responded. "It is like a large act of providence. I have been on several projects that were very nearly disastrous. Under the category of things that are very nearly disasters, I am surprised that there actually are not more accidents.

"At the end of my career at TransCanada, with the self-inspected welders, when I was told what they were doing, the exact same practices that we were doing in 2011, we were doing in the 1970s, and it resulted in a pipeline rupture in 1992. The problem is that, with pipelines, it waits a long time. Many times with the pipelines, it has to be disturbed before anything will happen. There has to be a ground movement or something like that. There are thousands of cracks in the system; it is just which ones will become the problem. It is low probability and high consequence."

Asked how he would know whether a situation was "very nearly disastrous," Vokes said, "If you had an 80 percent through-wall crack in a very large pressure vessel and you only found it because the inspector went out and had a look, that is very nearly disastrous for a plant that does not have a fire suppression system."

The NEB's investigation and an uptick in whistleblower reports to the regulator come at a time in which Canada, like the rest of the world, is at a major crossroads on energy. The Canadian petroleum industry expects fossil fuel extraction to increase, but it says there isn't enough pipeline construction underway to get the country's oil to tankers.Meanwhile incoming Prime Minister Justin Trudeau is set to attend the Paris climate conference that kicks off Nov. 30, where leaders will negotiate a binding deal to reduce emissions in an effort to keep global warming below two degrees Celsius.

Oil and gas companies may have legal challenges and environmental opposition in their path, but they're hopeful. Throughout the Canadian election, Trudeau has said he would reform the NEB and properly consult with indigenous leaders on pipeline proposals, which could mean more pipeline construction under the Liberals. Trudeau has especially favored Keystone XL and he hasn't said no to Energy East, which would come as good news for TransCanada.

But another former TransCanada employee echoes Vokes' worries about the company that could build Canada's next pipeline project.

Chris, whose name has been changed to protect his identity, worked for TransCanada on and off for more than 20 years, fixing pipeline ruptures and cracks like those that caused the Otterburne explosion. Unlike Vokes, he is not an engineer.

He alleges he saw a culture of worker inexperience and poor supervision that led to accidents, near misses, and unreported incidents. He raised these allegations in a whistleblower report to the NEB on September 4, 2014, which prompted the investigation released by the NEB on Friday. Chris also shared his whistleblower report with VICE News.

"Incompetent supervision out on the field and people not caring" are a problem, he said. "I see it every job I go to. It's disheartening to see a brand new pipeline damaged before they even backfill it."

Based on his allegations, the NEB found coating damage to a pipeline that appeared to go unreported for a year; an exposed, buckled section of pipe that was unnoticed for a year; an isolated mistake in welding procedures; a worker on site without protective equipment; an isolated incident of improper installation of ladders; and the over-torquing of a bolt that resulted in injury.

Whistleblower identified as Chris reported this pipeline to TransCanada and the NEB/Photo via TransCanada report

Speaking to VICE News, Chris elaborated on an incident in his whistleblower report. He was working on a four-month long project on the James River line, near Sundre, Alberta, a traditional oil and gas field about an hour's drive northwest of Calgary.

On June 27, 2013, Chris was on site with workers from a third-party contractor. They were young and inexperienced, he said. He noticed they were using the tools incorrectly, so he told the foreman. According to his allegations to the NEB, they used a hydraulic wrench to tighten flange bolts, but they tightened them over specifications.

At one point he said they put a piece of the pipeline in backward, which angered the foreman. They started taking it apart to fix it, he recalls.

Chris left for another site. Less than 10 minutes later, he received a frantic call — one of the workers had cut his finger off, Chris said.

"His finger was hanging on by just a [piece of] tissue," Chris remembers from a photo he was sent, but could not produce for VICE News. "The bones were coming out."

Chris believes the accident could have been much worse. "That bolt could have snapped off and hit someone in the head and killed them," he said.

"They kept it sort of hush hush," Chris said of TransCanada. Pipeline companies must report all serious injuries to the NEB. "They never reported it," he says.

According to the NEB investigation released Friday, TransCanada immediately shut down the site, started a safety investigation and entered the incident into its internal system. However, the NEB concluded, the worker's injury was "a pinched finger," a minor injury, and therefore TransCanada did not need to report it to the regulator.

The contractor told the NEB the workers had over-tightened a bolt 1.5 times over the specifications — not seven times over specifications, as Chris alleged.

Earlier on the same site, on May 18, 2013, Chris went to dig out a mainline for hydrotesting. He said he sat behind the controls of a excavator and started to dig when suddenly he hit a pipeline that, according to the drawings of the site, shouldn't have been there. The excavator left a chip in the pipeline coating, but did not pierce the pipe. He said he later saw more damage to the same pipe.

The foreman reported the incident to a TransCanada manager, Chris said. The site was then frozen for a few days to do an investigation, as is normal protocol. According to the NEB investigation, the pipe was inspected on June 6 and no mechanical damage was found.

Chris went on vacationfor about two weeks. When he went back to work on the same project, he saw the workers had patched the pipeline. But he claimed the patch wasn't up to code. "It was like a piece of tape covering a scar," he said.

Photo of patched up pipeline supplied by whistleblower identified as Chris.

"No, we can't do that," he recalls telling the foreman. He remembers the response was, "It's good to go, never mind."

He alleges the pipeline was put back in service without being fixed properly. It wasn't until May 2014, after he raised the issue repeatedly, that workers dug up the pipeline and repaired it properly.

"I pushed it and pushed it and pushed it, and finally they fixed it," he said.

However, the NEB investigation found that an unnamed TransCanada back-hoe operator told the company 10 months after the initial strike that there was a second potential strike at the time that had not been investigated, and the operator had not entered the strike into the company's system, as required.

The subsequent investigation confirmed there was a 3-inch-square area of unrepaired coating damage. It was then fixed.

Chris said it was not reported at the time to the NEB. However, according to the NEB's findings, TransCanada was not obligated to report the incident because it wasn't serious, and the pipeline itself was not damaged — only the coating on the pipe.

Chris believed the damaged pipeline could have corroded and eventually become dangerous, but the NEB found that none of his allegations, including this one, posed an immediate or long-term threat to the public.

In March 2014, Chris took a pipeline training course and realized his own training was not up to par.

After that, whenever he noticed something was not up to code, or was unsafe, he reported it internally to TransCanada and informally to the NEB. But, when he did so, he said, "I was told not to worry about that and that it wasn't my job."

Between March and September 2014, Chris says he met with former and current NEB employees, sometimes in informal settings over dinner and drinks, and told them what was happening at TransCanada. But from his perspective, there didn't seem to be any movement from the NEB.

One day, after he complained that ladders on a job site were set up in a way he believed could result in injury, he says his manager told him to go home and come back on Monday for a meeting.

When he came in for the meeting, someone from Human Resources was there and he was told he was no longer employed with TransCanada. He said they gave him a severance package but did not tell him the reason he was fired.

That same day, he met with the NEB and verbally detailed 12 allegations against TransCanada in a formal whistleblower report. It's unclear how and when those 12 allegations became the 16 allegations outlined in the NEB investigation.

It took the NEB a year and two months to investigate his complaints. Chris thinks the investigation was "a joke."

According to the NEB report, after Chris's allegations were submitted Sept. 4, the NEB met with TransCanada, and in late February 2015 the regulator requested evidence from the company, which it received in late March 2015.

When its investigation was completed, the board sent the company a draft of the report for comment "in accordance with the tenets of procedural fairness and natural justice."

Chris is critical of how long it took the NEB to respond to what he believed to be serious concerns.

"They gotta change something," he said, "because now my career is — I probably won't get another job on a pipeline."

NEB spokesperson Barter said the regulator takes steps to protect the confidentiality of whistleblowers, but does not have the legal authority to do anything if a whistleblower is pushed out of a company it regulates.

Vokes also takes aim at the NEB. He says the regulator is entirely to blame for TransCanada's shortcomings, and says the NEB lacks the teeth to change the status quo.

In 2013, before the Senate standing committee, Vokes said: "The most important thing the National Energy Board did is put the inclusion of whistleblower protection in the regulations recently. That is a very important thing. The second thing that is missing is this: What is the point of putting in a complaint if there is no change? That is the really important point."

Since Vokes blew the whistle to the NEB in 2012, there's been an increase in the number of whistleblower reports to the NEB, so much so that the regulator put out a tender for an expert to train its staff on how to handle the complaints.

Chris said the uptick could be due to increased education among pipeline workers like himself. The turning point for him was the pipeline training course. That was when he began viewing company practices as safety issues, and felt he needed to report them to someone who would listen.

"I'm just doing it for public safety," Chris told VICE News. "...I've seen what these pipelines do when they blow up, and eventually it's going to be in someone's backyard."

Watch the VICE News documentary Pipeline Nation: America's Broken Industry: