Superior police later tweeted that the fire had reignited and urged residents living within a one-mile radius of the refinery to leave.
"All indications are that the refinery site is safe and stable and the air quality is clean and normal", Superior Mayor Jim Paine said in a Facebook posting, noting that the evacuation order was lifted as of 6 a.m. local time (1100 GMT).
"I can see black billowing smoke, and it's lingering in the sky", said Bunny Vidotto, who lives in Superior, WI and is originally from Thunder Bay, Ont., in an interview with CBC News on Thursday.
David Morrison, an on-scene coordinator for the EPA, said technicians have been monitoring air conditions in the area around the refinery since the fire began.
"In one of the largest disasters this community has ever seen, everybody is going home", he said.
It was not immediately clear how many people were affected by the evacuation order. "And besides, we won some money", she said.
The extinguishing of the fire was initially problematic because once the asphalt ignited it produced smoke so thick and hot that the firefighters could not come near enough the fire to start putting it out.
Refinery manager Kollin Schade said six injured workers were taken to hospitals and seven others were treated at the scene following Thursday's explosion.
"Once we understood the full response plan, yes, I think it was our responsibility", he said, adding that he and his team meant to publicly lay out the potentially unsafe situation at a 7 p.m. press conference Thursday.
More than 24 hours after the explosion and fire at the Husky Energy Refinery some of the shock is starting to wear off. "That was the nature of the evacuation, ultimately. We've got to be pretty proud of our little city of Superior", Hale said.
"So while we were trying to be transparent, we were trying to truly protect the public as well", Paine said. The fire Thursday was later put out, and residents were told they could return to their homes.
Trianoski said her husband used to work at the refinery.
Husky Energy is working closely with federal agencies to understand the cause of the explosion.
Authorities in Superior say the explosion at the Husky Energy oil refinery happened at about 10 a.m. Thursday.
Schade said the unit that uses the chemical was not damaged.