Compiled by Imam Yahya ibn Sharaf al-Nawawi
وعن أبي هريرة رضي الله عنه قال: قال رسول الله صلى الله عليه وسلم : "الشهداء خمسة: المطعون والمبطون، والغريق، وصاحب الهدم والشهيد في سبيل الله" ((متفق عليه))
The Messenger of Allah (ﷺ) said, "The martyrs are of five kinds: One who dies of plague; one who dies of disease of his belly; the drowned; one who dies under the debris (of construction, etc.), and one who dies while fighting in the way of Allah." [Al-Bukhari and Muslim].