House Explosion In Michigan

[ConstitutionCowboy]

That's what I heard, that it was propane, not NG. IIRC, propane is heavier than air and settles, whereas NG is light and disperses?

Correct. The specific gravity of propane is 1.5219. Air is 1.000, and natural gas is between 0.6 and 0.7. (Source: The Engineering Toolbox.)

Woody

 

[Aries]

Smell it or not, at what concentration will natural gas or propane cause fainting, sickness, etc.? My search didn't reveal any specific data, only symptoms.

NOTE: There is a propane tank visible in the aerial photo of the destruction and on Google Maps.
ANECDOTE: I found a leak on my propane tank evidently because that mercaptan attracks flies!

Woody

Hmmm... not sure I know the answer to that, I guess at the point that your brain becomes starved enough for oxygen to be affected. Would probably depend not only on concentration, but also duration.

To be clear, I'm not commenting on this specific incident because I don't know anything about it. But what I said about the concentration for combustion and possibilities of not noticing an odor are universally true, but may or may not be relevant here.

Propane, btw is different and I have very little experience with that. It does seem like you're correct about attracting flies, although I can't say I ever found a leak that way.

 

[ConstitutionCowboy]

If a person has natural gas, I'd recommend keeping a canary around.

Woody

 

[Fredkrueger100]

I work for the gas company so I can say this about NG, it will kill you within just a few minutes. It can cause you to pass out within seconds. We had a tree grow into a meter setting one time and it broke the inlet connection loose and was leaking gas. When I got within a few feet of the meter I started getting a headache and hand to get away. Most people have no idea how powerful NG is. If it didn’t contain odorant, it would cause an enormous loss of life. That is why it is so important for our techs to properly maintain our odorant pots and to do our checks. That is one reason I’m glad I don’t work in the field anymore. I don’t have to deal with that stuff anymore. We have lost employees before due to NG inhalation. It took them down quick.

 

[Johnny]

The house looks like it has a full basement. If the propane leak stayed down there and there was no air circulation. The people upstairs may not have noticed for a few hours.