It happened at Economy Lumber near the corner of Coliseum and High Streets.
"It spread so fast, by the time the fire department came, the fire had spread to the top of the roof already," Sam Jebrial, a neighbor said.
Flanked by a gas station on one side and railroad tracks on the other, Oakland firefighters quickly called for this lumberyard fire to be four alarms, bringing more than 100 firefighters to the scene.
"The fuel load here was tremendous, like any lumberyard fire, so the crews on scene they started calling for alarms right away," Lionel Jarreau, an Oakland Fire Battalion Chief said.
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Come Monday morning, excavators were brought in to tear one of the lumberyard buildings apart.
"It's not stable, it's too dangerous, we can't send crews in there, we had a floor collapse on the second floor, so right now, the excavator's now tearing the building down so we can get to some of the hot spots" Jarreau said.
John Bacon, President of Economy Lumber, had a front-row seat.
"It was just too dangerous to go in and put the fires out," Bacon said.
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Bacon, seen going through the rubble at the business his family has owned for more than 40 years, pulling out what he could.
He estimates a few million dollars in losses.
"I could be depressed, I mean I'm sad, I just got my 35-year-old bike out of my office, I happened to see it when the building was coming down and he grabbed it for me, it's sad," he said.
Bacon says his business will be closed for the week while they re-evaluate what's next before starting the rebuilding process.
"We had to make do with this building, so we'll build something, more of what we actually need," he said.
He says of the four locations his family owns, none of their lumberyards has ever caught fire. This is the only location without fire sprinklers.
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Sam Jebrial, a manager of the gas station next door, says it was only a month and a half ago when he helped put out an encampment fire just outside of the railyard.
"I grabbed a couple of buckets of water, I dropped on it and I don't know this time I didn't see anyone but it could be, because they're lighting fires all the time," Jebrial said.
Firefighters say the cause of this fire is still under investigation at this time.