Inundation, fire or poison as aggravating circumstance

"That the crime be committed by means of inundation, fire, poison, explosion, stranding of a vessel or international damage thereto, derailment of a locomotive, or by the use of any other artifice involving great waste and ruin" is an aggravating circumstance.

An aggravating circumstance is one that makes the penalty for the crime committed heavier. Aggravating circumstances refers to factors that increases the severity or culpability of a criminal act. Typically, the presence of an aggravating circumstance will lead to a harsher penalty for a convicted criminal. https://www.law.cornell.edu/wex/aggravating_circumstances.

Unless used by the offender as a means to accomplish a criminal purpose, any of the circumstances (inundation, fire or poison) in paragraph 12 of Article 14 of the Revised Penal Code cannot be considered to increase the penalty or to change the nature of the offense. In short, the offender must have used said circumstance/s to specifically achieve the purpose of his crime.

When one of the three (inundation, fire or poison) already qualifies the crime, the other or others, if present, shall be considered as generic aggravating circumstance only.

Fire is not aggravating in the crime of Arson.

The crime is NOT "Murder with Arson" or "Arson with Homicide" when someone burns down a house to kill the person inside.

Whenever a killing is done with the use of fire, as when you burn down a house while someone is inside in order to cause his death, the crime is Murder. If the intent is to destroy property, the crime is only Arson even if someone dies as a consequence. If the intent is to kill , there is Murder even if the house is burned in the process.