The fire at a Becker recycling plant that burned for days and sent smoke billowing across communities northwest of the Twin Cities was extinguished Saturday.

Crews have shifted their efforts to cleaning up the site at Northern Metal Recycling, where thousands of junked vehicles went up in flames. Private firefighters hired by the company are expected to leave Sunday morning as the state fire marshal continues to investigate the cause and the Minnesota Pollution Control Agency (MPCA) monitors the air for particulate matter.

“It’s cleanup mode and hoping to move forward now,” Becker Police Chief Brent Baloun said.

Test results released Friday night by the MPCA showed no signs of metals in the air and low levels of particulates. Air tested near the plant was similar to air across the state that was not downwind of the smoke plume that came from the fire.

Even so, the state moved Friday to shut down the recycling company. Citing “imminent and substantial danger” to the public in its administrative order, the MPCA prohibited Northern Metal from accepting more scrap metal and operating its shredder, which grinds up vehicles.

Northern Metal had been preparing for the start of shredding operations, scheduled to begin Saturday, when the fire broke out early Tuesday. The burned vehicles were in storage on the site, ready to be shredded.

The company is now forbidden from operating until it completes a long list of required actions, including an environmental damage assessment, a cleanup plan and an updated plan for storing scrap metal. It cannot bring in scrap or use the shredder until the source and cause of the fire have been identified.