Atrocity (noun)

1. An extremely wicked or cruel act, typically one involving physical violence or injury.
2. A brutal deed or act.

Origin:

Late 16th century: via latin from greek atrocitas, from atrocē "abominable", from atrox "cruel".

Examples:

1. The atrocities committed during the war still haunt the survivors.
2. The dictator was accused of committing numerous atrocities against his own people.
3. The reports of the atrocity shocked the world.
4. The victims of the atrocity were left with physical and emotional scars.
5. The international community condemned the atrocity and called for those responsible to be brought to justice.