A contractor working at the Husky Energy refinery in Superior said the April 26 explosion sent him 15 feet into the air, resulting in severe injuries when he hit the floor, according to a lawsuit filed against the refinery and its owners.

Contractor Taylor Mayr of Houston, Texas argues in a November complaint filed in U.S. District Court in Madison that Husky Energy, Inc. and Superior Refining Company LLC were negligent in operating the refinery, conducted "extra hazardous and/or ultrahazardous and abnormally dangerous activities" and are responsible for over $75,000 in damages to him because the blast left him with "permanent and severe injuries."

Mayr, employed by Evergreen North America Industrial Services and tasked with chemical cleanup as the refinery shut down for maintenance in late April, was working near the fluid catalytic cracking unit, where the explosion occurred as crews worked to shut it down for planned maintenance, according to the compliant.

When the blast occurred shortly after 10 a.m. on April 26, "The initial shock wave caused by the explosion launched (Mayr) fifteen ... plus feet in the air and hurled him to the floor," the complaint states. "As a result (Mayr) suffered severe injuries."

The April 26 refinery explosion and subsequent asphalt fire led to 36 injuries, according to the U.S. Chemical Safety and Hazard Investigation Board, and prompted the evacuation of much of Superior.

Lawyers representing Mayr did not respond to News Tribune questions Monday afternoon about the extent of Mayr's injuries.

Husky Energy also did not respond to a request for comment by the News Tribune Monday afternoon.

Citing the U.S. Chemical Safety and Hazard Investigation Board's ongoing investigation into the blast, Mayr's complaint argues Husky "failed to exercise due care in the maintenance and monitor of the Husky Superior Refinery so as to prevent fires, explosions, or other harm to individuals, including (Mayr)."

In August, the board said a worn-out spent catalyst valve within the fluid catalytic cracking unit allowed air to mix with hydrocarbons, creating an explosive mixture which then contacted an ignition source.

Then in October, the Occupational Safety and Health Administration, said the company's Process Hazard Analysis - a document explaining risks involved in an industrial process, and operating procedures - failed to address what might happen if the valve seal failed.

Although OSHA and the board conduct separate investigations, additional information released by the board in December mirrored OSHA's findings.

The board said the refinery's "process hazard analyses," also described by the board as a "safeguard," only considered what would happen when the valve was open, not what would happen if it was closed but unable to hold a seal.

Mayr's lawsuit is not the first filed against Husky Energy and Superior Refining Company in the wake of the refinery explosion and fire.

A lawsuit filed by contractors in August claims workers heard a "strange knocking noise" shortly before the explosion, but were ordered to return to work after they expressed concern. The explosion then occurred within 30 to 40 minutes of returning work, the lawsuit said.

A class action complaint filed by several Superior residents in August argue Husky displayed negligence, nuisance, trespass on land and strict liability - extrahazardous and/or ultrahazardous activity before, during and after the fire and evacuation.