I was looking for something else entirely when I stumbled across this picture:
Now, I'm not an expert by any stretch of the imagination. I don't work for anyone who is an expert and I haven't been trained as an expert. However, it seems very odd to me that this explosion is being described as a "furnace" explosion. Maybe it was. In all honestly, it probably was. Still, the fan-shaped debris field looks awfully suspicious to me. Below are a number of pictures of meteor and rocket craters/impact sites. Notice that they all feature the same, very distinct, fan-shaped debris field.
Here are the news reports about the house explosion:
ABC News: Deadly Explosion in Indianapolis Neighborhood
Twice: Indy Audio's Longworth Dies in Explosion
Centre Daily Times: Deadly Blast Devastates Indianapolis Neighborhood
Komo News: Furnace May Be Behind Deadly Blast
Last of all, here is John Dion Longworth's LinkedIn page:
LinkedIn: John Dion Longworth
Now you have all the information that I have. Perhaps it is nothing. I hope it is nothing. While it is tragic that two people have died, I hope that in the end it proves to be nothing more than a simple furnace explosion. All of the other possibilities are too terrifying to consider.
Update: December 22, 2012
The authorities have determined the tragedy was arson. Apparently it was just another attempt to defraud an insurance company by three desperate homeowners.
News-Sentinel: 3 Set Off Deadly Indianapolis Blast