Minnesota ? Authorities evacuated this southeastern Minnesota town of about 3,600 Friday as a large fire at a meat processing plant threatened the anhydrous ammonia tanks inside but, despite a scare, firefighters were able to prevent the tanks from exploding.

While Police Chief Bill Eckles had said he received word from the command center around 8 p.m. that one of the tanks in the North Star Foods plant had burst, Kristine Hernandez, a spokeswoman for the emergency operations center for the incident, later said it turned out the tank didn’t blow.

What happened, Hernandez said, was that as crews were deliberately venting ammonia from the five tanks inside the plant, some ammonia in the pipes that run through the plant escaped, causing ammonia levels in the air to temporarily spike twice. She said the ammonia dissipated right away and posed no threat to emergency workers at the scene.

Hernandez also said officials hoped to let residents return home today.