A, B, C, and D, all armed with armalites, proceeded to the house of X. Y, a neighbor of X, who happened to be passing by, pointed to the four culprits the room that X occupied. The four culprits peppered the room with bullets. Unsatisfied, A even threw a hand grenade that totally destroyed X's room. However, unknown to the four culprits, X was not inside the room and nobody was hit or injured during the incident.

Are A, B, C, and D liable for any crime? Explain.

Yes. A, B, C, and D are liable for destructive arson because of the destruction of the  room of X with the use of an explosive, the hand grenade. Liability for an impossible crime is to be imposed only if the act committed would not constitute any other crime  under the Revised Penal Code.

Although the fact involved are parallel to the case of Intod vs. Court of Appeals (215 SCRA 52), where it was ruled that the liability of the offender was for an  impossible crime, no hand grenade was used in said case, which constitutes a more serious crime though different from what was intended.