Old Blue Heron paper mill in Oregon City on fire

Clackamas Fire District #1 responded to a fire on Saturday at the old Blue Heron Paper Mill in Oregon City.

The fire began at around 3 p.m., according to a post on the department’s Twitter.

The fire department says the building quickly became structurally unstable. That forced firefighters to exit the building and spray water from above.

Both Highway 99 and the train tracks in the area closed briefly. Firefighters and investigators remained on the scene throughout the night and into daylight hours to determine what caused the blaze.

The Confederated Tribes of Grand Ronde purchased the closed Blue Heron paper mill site, located on the Willamette Falls, last year.

Since making the purchase, Grand Ronde tribal leaders have teamed up with the Willamette Falls Legacy Project — a collaboration between Oregon City, Clackamas County, Metro and the state to develop a “Riverwalk.”

The Riverwalk project was initially set to break ground in the spring of 2020 — creating access for the public to Willamette Falls and the river.

The Willamette Falls Legacy Project said in a statement earlier this year that the original groundbreaking date “has shifted,” but has not released an updated timeline.