Narrated Abu Huraira: Allah's Apostle said, "Five are regarded as martyrs: They are those who die because of plague, Abdominal disease, drowning or a falling building etc., and the martyrs in Allah's Cause."
Hadith ReferenceSahih Bukhari / The Book of Jihad (Fighting For Allah’S Cause) / Hadith: 2829
Hadith Gradingمحدثین:أحاديث صحيح البخاريّ كلّها صحيحة