Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) asked: Whom do you consider a martyr among yourselves? The people replied: The one who is killed in the way of Allah is a martyr. The Prophet (peace and blessings be upon him) said: The one who dies in the way of Allah (while going for jihad or Hajj) is a martyr, the one who dies due to plague is a martyr. The narrator states: Ubaydullah bin Maqsim narrated this hadith to me, and he says: I testify regarding your father that he also narrated these words in the hadith: (The one who drowns) and dies is a martyr.
Hadith Referenceصحیح ابن حبان / كتاب الجنائز وما يتعلق بها مقدما أو مؤخرا / 3187
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - انظر ما قبله.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح