I saw A story like that on a real life crime show. A very frugal landlord replaced a furnace but did not want to pay for the installation so he did it himself. He did something backwards so the thing blew up killing a young couple. Terrible.
I remember that episode. We watch WAY TOO MUCH ‘Crime TV’ in this household, LOL!
But, once I plan that Perfect Murder, it will have all been worth it. *SMIRK* :)