Oil giant BP has slashed the majority of the contractors at a refinery in Ohio after a massive explosion and fire which saw two brothers killed.
The refinery in Toledo will be closed for an extended period of time after the incident last week, which saw two United Steelworkers members, brothers Max and Ben Morrissey, killed.
The refinery, which is more than 100 years old, has been shut down since the middle of last week and could remain closed for several months.
BP jointly owns the site with Cenovus Energy Inc.
At least one contracting firm is on the site inspecting the damage and the US Chemical Safety Board is also looking into the situation.
It is thought the blast happened due to the emission of sulfur dioxide and hydrogen sulfid, which has led to considerable property damage but the official cause of the explosion has yet to be determined.
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A source told Reuters the leaking gases from a crude unit may have prompted a fire in another unit at the plant.
They said many units were engulfed in flames.
Cenovus said in August that it will purchase the remaining 50 percent stake in the BP-Husky Toledo Refinery that it does not currently hold.
The transaction is scheduled to be completed by the end of 2022.
Husky Energy launched a joint venture with BP in 2008 by purchasing a 50 percent share in the Toledo refinery.
When Cenovus merged with Husky in 2021, the interest was transferred to Calgary-based Cenovus.