TH arson investigator gives insight to Indy explosion

TERRE HAUTE, Ind. (WTHI) - Arson investigators work around-the-clock trying to piece together the cause behind a deadly neighborhood explosion on the south side of Indianapolis.

An explosion that took out several homes sending debris flying throughout the neighborhood has yet to be solved.

Investigators have been working around the clock since Saturday to determine a cause.

A Terre Haute Arson Investigator Norm Loudermilk explained to News 10 how the investigation will work.

"Most investigators on fires or explosions investigate from the outside going in. Why; because they want to get the big picture that will lead them to the small event which is where it started,” said Loudermilk.

The explosion left debris scattered for blocks.

Loudermilk said every piece of debris will be examined to help determine what happened.

“One of the best ways to investigate is what’s called a grid method. Then you can identify what item came from what grid. You can track that on paper or a computer and you can recreate the scene back in your office or back in a lab and be able to put those items together,” said Loudermilk.

The process is slow and takes time. Loudermilk said it may be months before officials can piece the puzzle together.

Loudermilk said, "It isn't over until it’s over and that's the way it is. You investigate until you came up with a cause, until you came up with an origin and an ignition source. You can’t stop until then.”

Loudermilk said gas caused the explosion; it's just a matter of determining where the gas came from and what kind.