SUPERIOR, WI — Officials have lifted a mass-evacuation order for the nearly 27,000 people living near or around the Husky Oil Refinery in Superior after explosions and fire erupted at the facility Thursday.

Superior Mayor Jim Payne said all evacuation orders - which were enforced by police by going door-to-door in many neighborhoods - were lifted at 6 a.m. Friday. "All indications are that the refinery is safe and stable and the air quality is clean and normal," he said in a public statement. On Thursday night, eight hours after a series of explosions and a massive fire were first reported at the Husky Energy refinery, Payne relayed a message to residents living in the more than 70 square miles around the plant: "Breathe easy, this fire is out."

Just after 7 p.m. Thursday, Gov. Scott Walker tweeted that he was on his way to Superior to speak with local officials and to get a report of the damage. In Superior looking at the damage from the air. Now headed out to meet with local officials on the ground. pic.twitter.com/o2yx15TNNg

— Governor Walker (@GovWalker) April 27, 2018 Explosions Rock Superior Area

Initial explosions that occurred at about 10 a.m. Thursday injured at least 11 people, the Associated Press reports. The Superior Fire Department intially reported there could have been up to "20 casualties." There were no deaths, however, Deb Stein of Douglas County Emergency Management told Patch.

A second round of explosions happened at about 12:30 p.m. A report out of CBC News says that a tank containing crude oil or asphalt exploded, prompting fire officials to urge people living near the still-burning plant to leave their homes.

Throughout the day, firefighters struggled to approach the blaze, which was fueled by industrial chemicals and petroleum products, according to multiple reports, including the Minneapolis Star Tribune.

By late afternoon, a crew of about 30 firefighters was able to get "enough water and enough water pressure" to quell the flames and eventually extinguish it, the newspaper reported.

A Husky Energy spokesperson said the fire broke out in the fluidized catalytic cracking area of the refinery. This is the area of the refinery where crude oil is separated or "cracked" into different petroleum products. Workers Hospitalized