The NTSB has released their preliminary findings about the explosion and fire at Zimmy’s Tavern.

On Wednesday, officials said they found natural gas underground on nearby properties and inside the sewer system, consistent with a leak in the system. A leaking fusion joint was found during the investigation. Their report shows the lines were installed in 1988.

They caution that they have not yet determined a probable cause and all aspects of the incident remain under review.

Meanwhile, the worker who was injured and taken to a Kalamazoo burn unit is expected to recover from his injuries.