A series of water pipes had burst in the basement that morning, which the mill workers surmised was a result of three -40 C days and then a rapid jump in the mercury.
The 27-year-old watchman security officer descended alone into the mill's bowels to check out the situation.
He had spotted unusual pools of water on the ground when the fire alarm began shrieking.
While ducking under a waste conveyor to investigate, a bottle of water dropped from his vest pocket.
He pulled off his right glove, scooped it up and twisted open the cap.
"Took a swig. Lights flickered. Then just a flash, a shock wave or a flash or whatever pushed me to the left," he recalled.
"Then, I believe, it just came back towards me again and pushed me to the right. Knocked myself on my butt."
The explosion flung his glasses and helmet. Searing heat tore skin off his nose and cheeks. He jammed his eyes shut.
But he knew the way to the exit. Debris everywhere, he clambered over a massive compressor machine. Flames leapt up all around him.
He was out in two minutes.
"I basically collapsed on my knees in the snow. Just huddled down, tried to get my (bearings). It was pain. I was trying to compose myself," he said in an interview two days after the blast that destroyed the mill and has left the small town reeling.
Nguyen suffered first and second degree burns, peeling layers off his face and right wrist and hand in chunks. Sitting in his family's restaurant on the village's main drag on Sunday, he wiped dripping ointment out of his eyes as he choked back a sob.
Two First Nations men, Carl Charlie and Robert Luggi, are missing and presumed dead, while 18 others were rushed to hospital, including four who remained in critical condition.
By Sunday afternoon, though, the remains of one individual had been found amidst the burned-out mill, and by Monday afternoon, the remains of a second individual had been found, announced the BC Coroners Service.
The service said because of the explosions and the devastating nature of the fire, further tests are required to identify the individuals.
"It is overwhelming. I feel that it was a miracle that I actually did stop where I was," Nguyen said in stilted breaths. "If that water bottle didn't drop out of my pocket, I would have kept going towards that fire."
Ernie Nesbitt has just one small burn mark on his elbow from the blast.
The 36-year veteran was at work in the round-saw room in another part of the mill when he felt the concussion wave pass.
"It was a hell of an explosion," he said, face pale and pointing to his arm. "How's that? And we've got people that are missing. So 99 per cent of this is luck."
He opened the round-saw room door. On the other side there was no wall and no roof.
Someone with burns was calling 911.
"I was in a dead air space ... Our back door is blown out, light bulbs (have) disappeared. And I'm standing there going, 'What's happening?'"
Nesbitt said he did what anyone would do for the guys he worked beside day after day. His eyes were bloodshot as he recounted the harrowing memories inside a town hall where more than 100 people gathered to share food and grieve together.
He named co-workers who helped swiftly move the injured people out.
But another mill worker and friend who asked to remain nameless described Nesbitt's actions as heroic.
"He lifted one guy who was trapped under some sort of wood or beam, dragged him out to safety. And three other guys he led were almost blinded from all the explosion stuff, the dust," said the 33-year worker.
"One at a time, he dragged them back to safety, and almost feeling his way through the dark, because all the lights were out.
"He's a big strong guy with a big, big heart, one of the bigger hearts I've ever met in anybody and he saved four people's lives."
Three pumper fire trucks trucks raced to the mill, and sucked two "deep wells" dry trying to douse the flames, said Fire Chief Jim McBride. Investigators were ultimately waiting for the embers to burn out before entering the site to search for remains and deduce what happened.
Nguyen said unlike others' reports, he did not smell any gas when conducting his checks between his 6 p.m. start and the 8:15 p.m. blast. He believes a natural gas pipe likely burst, though has no idea what was the spark.
But the eight-year employee and other workers had noticed excessive build-up of sawdust in recent years, which he's sure fuelled the fire that has destroyed the multi-million dollar main mill.
He also said that only two weeks ago, he and two co-workers were equipped with only fire extinguishers and garden hoses to knock down a fire that began when the trio were alone in the building.
"That's not adequate," he said, adding he believes some better procedures should have been in place.
Most pressing for him, as townsfolk entered the diner to wish him speedy recovery, was a simple message.
"I'd really like to thank all the hospital crew and maintenance road crews and all the people that helped us out."