Sa'd bin Ubadah (may Allah be pleased with him) was killed by the jinn

It is narrated from Muhammad bin Sirin that Sayyiduna Sa'd bin Ubadah (may Allah be pleased with him) came to the rubbish heap of a people and urinated there standing, then suddenly fell down dead. Thereupon the jinn said (these verses): "We have killed the chief of the Khazraj, Sa'd bin Ubadah; we shot him with two arrows, and they did not miss his heart."

It is narrated from Qatadah that Sayyiduna Sa'd bin Ubadah (may Allah be pleased with him) remained for a time unable to urinate. Then, when he returned, he said: "I feel something (some pain) in my back." Not much time passed before he died, and the jinn lamented, saying: "We have killed the chief of the Khazraj, Sa'd bin Ubadah; we shot him with two arrows, and they did not miss his heart."

It is narrated from Sayyiduna Anas (may Allah be pleased with him) that when news of the approach of Abu Sufyan's (trade caravan) reached the Messenger of Allah (peace and blessings be upon him), Sayyiduna Abu Bakr (may Allah be pleased with him) spoke, but he (peace and blessings be upon him) turned away from him. Then Sayyiduna Umar (may Allah be pleased with him) spoke, and he (peace and blessings be upon him) turned away from him too. Then Sayyiduna Sa'd bin Ubadah (may Allah be pleased with him) said: "O Messenger of Allah, by the One in whose Hand is my soul, if you were to order us to plunge into the sea, we would plunge into it; and if you were to order us to drive our mounts hard (at speed) as far as 'Bark al-Ghimad' (an extremely remote place), we would certainly do so." So the Messenger of Allah (peace and blessings be upon him) called the people (to prepare), and they all set out until they encamped at Badr.
This hadith is sahih (authentic) on the condition of Muslim, but the two Shaykhs did not record it.