Actually, many of the home fires from cheap Lipo batteries have been found to have defective chargers that cause the batteries to catch fire. Many of these cheap Chineseium chargers are poorly built and short out causing the fires. While the Lipo batteries can be an issue, the majority of fires studied came from faulty chargers.
It's almost always a cheap charger and or poor quality batteries with horrible battery management causing the fire. We get calls nearly non-stop for them. It's almost never a name brand component but rather a off brand/lower quality piece. The cordless drill components and the like are under way better quality control. You do occasionally get an old laptop and old phones.
We have had a few where the bike was parked after a ride and the battery went up, no charging or nothing. Just ignited sitting parked. I suspect either it was heat related or the pack was damaged at some point. There typically isn't much left once we get there to take a look.
I don't not trust good quality components but it's just that. I'd charge outside and away from anything flammable.