Wayne, MI – DETROIT (WXYZ) – If history is a guide it will be years before we get a final answer on what caused Wednesday’s devastating blast in Royal Oak.

It was more than two years ago that a furniture store in Wayne was leveled by an explosion and the Michigan Public Service Commission still has not issued its report on what caused it.

But 7 Action News Investigator Scott Lewis tracked down someone who says he knows what caused the furniture store to explode, and it didn’t take him long to figure it out.

He’s the fire marshal in Wayne.He says based on his years of experience he believes the deadly furniture store explosion was caused by natural gas and he’s figured out exactly how it happened.But he doesn’t have the final say.

It was another horrific explosion that dominated the TV airways for days.In December of 2010, Franks Furniture in Wayne was rocked by a blast that left two people dead and the store owner seriously burned.

That was more than two years ago, and we are still waiting for the Public Service Commission to give us their final word on what caused the blast.

But Wayne Fire Marshal John Adams says he knows what caused it, and it only took him a few days to reach his conclusion. Once he determined there was nothing inside the building to cause such a violent explosion, it pointed to only one thing.

“Now it really steered itself to natural gas as being the only reasonable explanation for such an explosion to occur,” said Adams.

And before long, Adams also knew how the gas explosion happened.

Adams told 7 Action news there was a fence installed on the property.He says when they put the posts in the ground the downward pressure separated a natural gas line.And right next to that high pressure line was a 40 year old sewer pipe.

“Now you have that gas which is flowing excessively, at that point it has to go somewhere. And it typically will take the path of least resistance,” Adams said.

Adams determined that the path of least resistance in this case was the sewer line which filled the building with explosive natural gas.Because gas is lighter than air, it rose to the top of the store and filled the building. The heating and cooling system was located on the roof.

“As it kicked on, because it was in the winter, it was December 29, 2010 it ignited the product and hence the explosion that we had,” said Adams.

When they manufacture natural gas they put a chemical in it that smells like rotten eggs so if there’s a leak you’ll smell it and you can get to safety.So why didn’t that happen with this furniture store in Wayne?

Adams has an explanation.

“Under unique conditions in this where it was forced into the ground, and the ground acts as a scrubber, separating that additive that was applied to the natural gas .”

But if the fire marshal figured out what caused this in a few days, why are we still waiting for the Public Service Commission’s final word on the cause two years later?Adams says when lawsuits are filed, as they were in this case, the utility is not going to go with the Fire Marshall’s conclusion.

“So they don’t always take that as factual opinion.They’ll seek other experts to support their particular opinion on the incident,” said Adams.

Attorney Jules Olsman represented store owner Paul Franks who was badly burned.Consumers Energy settled out of court, even though they never conceded that natural gas was the cause of the blast.

“They may not be saying we’re responsible, but they’re there to say we’re not here to argue whether we’re responsible we’re here to deal fairly with the people, and they do. ”

Olsman says he thinks we are likely to see more of these deadly explosions because our utility infrastructure is so old. He says people worry about the interplay between the utilities and the government agencies that investigate and veracity of their reports.For that reason, he says, these investigation should be more open to the public.

By the way, Consumers Energy issued their own report one year after the furniture store exploded listing three possible causes for the blast.One of them was natural gas.