US refinery explosion and fire injures 15, causes mass evacuation
27 April 2018
An explosion at a refinery in Superior, northwestern Wisconsin, injured at least 15 on April 26 and caused the evacuation of tens of thousands of local residents. The resulting fire was extinguished after two hours but covered the surrounding area in noxious smoke, and local authorities only gave the all-clear for residents to return to their homes the following morning.
One of the casualties was said to be seriously injured, and nine others were also admitted to local hospitals.
CBS said in a report that a tank of crude oil or asphalt had exploded at refinery, which is owned and operated by Husky Energy. After an initial blaze was extinguished, a storage tank was punctured and a second fire erupted, a company spokesman said, and another tank caught fire later.
“Our focus in the days ahead will turn to the investigation and understanding the root cause of the incident,” Husky Energy said.
The refinery had additional workers on site preparing for a plant-wide overhaul when the blast occurred, the spokesman said.
During a news conference on April 27, Superior Mayor Jim Paine said the fire had the potential to be “absolutely catastrophic” because of the proximity of a tank containing hydrogen fluoride to the seat of the blast and fire.
He said the evacuation order covered 40,000 residents of the city and neighbouring communities because of the risk of a release of the chemical, a fast-acting acid that can cause severe burns.
The US Chemical Safety and Hazard Investigation Board (CSB) has sent a four-person team to investigate.
Alberta-based Husky Energy bought the refinery from Calumet Specialty Products Partners last year for over $490 million. The Occupational Safety and Health Administration (OSHA) fined Calumet Superior LLC $21,000 over emergency response and flammable liquids violations in 2015. The violations were settled and the problems resolved by the end of that year, according to CBS.
The Superior refinery has a processing capacity of around 50,000 barrels per day and a storage capacity of 3.6 million barrels of crude and products. It processes both heavy crude from the Canadian tar sands in Alberta and lighter North Dakota Bakken crude.