A gas explosion in a house would likely cause a ton more damage, so it’s probably not the case, but it might explain how so many members of the family are aware of what happened, and perhaps why Kate feels so much guilt if her father died saving her.
Perhaps there was a gas leak and Jack arrived home to a room of his passed out family and rushed to get them out.
This one is a bit of a stretch, as all the Pearsons in the wake of Jack’s death didn’t appear to have smoke on them or anything, but it’s possible.
Something sparks, there’s an explosion, and Jack is gone in an instant.