Investigators are working to determine the cause of a late-night fire Saturday that destroyed a building at a northeast Minneapolis lumberyard.

The blaze, reported after 11 p.m. at Shaw Stewart Lumber, 645 Johnson St. NE., filled the skies with flames, embers and plumes of smoke just east of busy Interstate 35W.

There were no injuries.

On Sunday, firefighters were at the scene until about 1 p.m. pouring water on hot spots in the smoldering ruins, Deputy Chief Todd White said.

Investigators also went through the rubble and left the lumberyard about 1 p.m., as well, he added.

White said he did not know when the investigation would be completed.

The fire was reported by a passerby in a car.

"It went from a little bit of smoke to fully engulfed in flame in just minutes," Battalion Chief Stephen Dziedzic said.

About 35 firefighters worked to keep the fire from spreading to nearby buildings, Dziedzic said.

White said the crews were fortunate to have a calm night, with no heavy winds or extreme cold, to aid efforts to fight the fire and keep it contained.

The bulk of the blaze was extinguished after midnight.

Dziedzic said no one was believed to be at the locked lumberyard at the time of the fire.

Staff Writer Anthony Lonetree contributed to this report.

Vince Tuss • 612-673-7692