Washington, DC, May 2, 2018 – A four-person investigative team from the U.S. Chemical Safety Board (CSB) is investigating the scene of the April 26, 2018, explosion at the Husky Energy oil refinery in Superior, Wisconsin. The refinery was shutting down in preparation for a five-week maintenance turnaround when the incident occurred. At least 11 people were reported to be hurt and several workers sought medical attention.
Thousands of residents near the refinery were asked to evacuate due to heavy smoke. The evacuation order that was issued by the Mayor of Superior Town has been lifted for all areas.
The product involved in the explosion and fire is believed to be crude oil or asphalt.
The investigative team from the CSB arrived in Superior the evening of April 26. They are conducting interviews and reviewing evidence, including incident photos and documents. The initial, onsite phase of the investigation is expected to take several weeks. During this stage, the investigative team will focus on the following tasks:
• Documenting and collecting physical evidence.
• Photographing the refinery and the incident scene.
• Interviewing Husky employees and contract employees involved in activities potentially pertaining to the incident.
• Obtaining documents related to the tasks being performed at the refinery around the time of the incident, including work plans, site safety plans, hazard analyses, and job safety analyses.
• Obtaining construction, maintenance, and inspection records of equipment suspected to be involved in the incident.
• Reviewing the effectiveness of emergency response to the incident including evacuation efforts.
Review of the preliminary investigation results will determine the need for additional materials testing or interviews with employees.
The CSB will continue to provide updates to the public as the investigation unfolds.