Depending on the situation, a number of different parties could be held responsible for an explosion or fire. Here are a few examples:
Guests, tenants, or property owners adjacent to where the fire or explosion occurred. It is possible that improper use of grills, smoking, or the presence of flammable materials could have caused the blaze.
Landlords may be held responsible for an explosion or fire if the proper security features – such as fire alarms or smoke detectors – failed to go off or were not installed.
Manufacturers and designers of products may be held liable if a defect led to an explosion or fire.
Contractors who incorrectly installed appliances or faulty wiring may be held responsible if their shortcomings led to an explosion or fire.
While these are a few specific examples, any number of parties could be held liable for an explosion or fire. It always depends on the specific circumstances, extent of damage, and initial cause.