Abandoned houses almost always have utilities shut off, with no one paying the bill. Although we play a game on construction sites, theorizing how to make equipment catastrophicly malfunction in case we ever need to grease someone and not get caught. There are a surprising amount of ways to make gas-fired household appliances ignite themselves
Here's a couple of fun ones, that I was directly involved with...
I was leased a home, one year rent free, on the proviso that I made it habitable.
(The owners paid for all materials, but I provided the labour for free)
The gas was turned off and red-tagged.
One night, a squatter came in, and turned on the gas main.
There was a huge plume of black dust on an internal wall, emanating from the open end of the main, in the kitchen.
Fortunately for me (and the house) the squatter turned the gas main off again, and didn't return.
Another home, belonging to a friend, had all the floors sanded and varnished.
Despite many instructions to turn off all appliances, and the gas main, before this work started, she left the hot water service turned on, and the pilot light lit.
(The service was inside the laundry of this home.)
The resulting explosion, caused by fumes from the curing varnish, broke every window and external doors and caused many painted areas to catch on fire. She was very lucky that the house wasn't destroyed.
