A civil trial is expected to open on Monday, stemming from a fatal 2012 explosion aboard a U.S. Gulf of Mexico platform.

The explosion and fire aboard the Black Elk Energy-operated West Delta 32 platform resulted in the tragic deaths of Ellroy Corporal, Jerome Malagapo, and Avelino Tajonera, serious injuries to others, and the discharge of pollutants into the Gulf of Mexico.

An investigation by the U.S. authorities later revealed that the explosion and fire occurred when hydrocarbon vapors ignited while a worker was welding on the incoming pipe segment to the wet oil tank located in the Lease Automatic Custody Transfer (LACT unit) area. The ignition started a chain reaction that caused the wet oil tank and two connected dry oil tanks to explode.

According to the Associated Press, the case opening on Monday involves nine lawsuits. The plaintiffs are the relatives of the deceased, injured workers, and the companies who did work on the affected platform.

The news agency says that the trial will take place in several phases