The tug Nathan E. Stewart ran aground because the crew member on watch at the time fell asleep, missing a course change near Bella Bella on B.C.'s central coast, a report from the U.S. National Transportation Safety Board says.
And company safety procedures that might have averted the accident – including policies that required an additional person to be in the wheelhouse at certain times – were not followed, the report concludes.
The report, released Nov. 21, sheds more light on the incident in October, 2016, that released nearly 110,000 litres of fuel and oil into coastal waters.
The accident occurred in the traditional territory of the Heiltsuk Nation, whose tribal council has since pushed for a marine response centre led by First Nations on B.C.'s Central Coast.
"We are shocked and appalled at the lack of safety measures," Marilyn Slett, chief councillor of the Heiltsuk Tribal Council, said in an interview on Friday, referring to conclusions in the NTSB report.
Ms. Slett said the report is the first confirmation she has heard of what happened that night. The Heiltsuk are preparing to take legal action, and this new information will be helpful to that effort, she added.
The accident involved a tug, the Nathan E. Stewart, and a fuel barge. The Nathan E. Stewart routinely travelled from petroleum facilities in Washington state or B.C. with tank barges carrying refined petroleum products destined for ports in Alaska. The U.S. board conducted a review because the tug sank on a waterway between Alaska and Washington state in the Inside Passage.
The tug's owner, Kirby Offshore Marine, "specifically addressed in the company's safety management system (SMS) the transits through the Alaska waterways and the Inside Passage," the NTSB report says.
Kirby's SMS had written procedures "that required an additional watchstander in the wheelhouse with the licensed deck officer while the vessel was operating in pilotage waters," the NTSB report says.
Based on statements of the crew and the lack of documentation in the vessel's logbook or elsewhere, "there is no evidence to support the conclusion this SMS procedure was implemented," the report says.
Investigators found that shortly before the accident, one of the crew on watch attempted to contact the second mate, who had command of the bridge, by a hand-held radio and received no response. He was making his way to the upper wheelhouse when he felt what he described as "shuddering." It was then that the second mate told him the tug, which was pushing an empty oil barge, had run aground.
According to the captain, the second mate – in a discussion about an hour and a half after the grounding – admitted he fell asleep before the accident, the report said.
The second mate confirmed that admission when interviewed by investigators after the accident, the report says.
An official for Canada's Transportation Safety Board said on Friday its own investigation of the tug grounding is not yet complete.
The crew of the stranded vessel initially resisted offers of assistance from the Heiltsuk – who were first on the scene. But the tide was dropping, increasing the pressure on the hull.
The tug's crew of seven eventually accepted a rescue from the Canadian Coast Guard, but an estimated 110,000 litres of fuel, as well as engine lubricants, were lost as the hull was breached on the rocks and the tug sank.
The Heiltsuk have said they will look to the courts for compensation for the loss of commercial harvesting of marine resources, as well as infringement of their aboriginal rights to harvest for food and ceremonial purposes.
B.C.'s Minister of Environment and Climate Change Strategy, George Heyman, was not available for an interview Friday.
His office sent a statement attributed to him.
"The Heiltsuk Nation continues to be impacted by the spill from the Nathan E. Stewart, and I expect this news will be particularly troubling for them. I can certainly understand the frustration and anger they've felt," the statement said.
"The federal government is making significant new investments in marine spill response and recovery and that's welcomed. But this finding reinforces the fact that human error is a factor, and the federal government needs to ensure those who are moving products off our coast are adequately prepared to respond to a spill and restore any damages to the marine environment as well as address socio-economic and cultural impacts to First Nations and coastal communities."
Kirby was not immediately available for comment.