The Tragic Death of Prophet Muhammad and His Family

References:
Tafsir Qur'an, Surah Ali 'Imran (3), v. 61 by Ibn Kathir, Tabari, al-Jalalayn
al-Tabari, vol. 9 page 187.
Ansab Ashraf, by al-Baladhuri, v1, pp 582-586
Tareekh Ya’qubi, v2, p116;
al-Imamah wal-Siyasah, by Ibn Qutaybah, v1, pp 19-20.
The Tragic end – Muhammad’s Family Destroyed -7 (educatedmuslim.com)

The Prophet did the Mubahalah (tafsir Qur'an, Surah Ali 'Imran, v. 61) against the Christians of Najran in October of 631. He thought he was the winner when the Christians didn’t come around. Instead he died in June of 632, less than a year from the Mubahalah.
All his family that came to the Mubahalah, Ali, Fatima, Hasan, Huseyn died in terrible ways.
The Prophet said in Qur'an, Surah Al-haqqah, v. 44-46 that Allah would cut his aorta if he made up Allah’s words. But then in Bukhari he claimed Allah had done just that and caused him to die.
Sahih al-Bukhari 4428
Narrated `Aisha: The Prophet (ﷺ) in his ailment in which he died, used to say, “O `Aisha! I still feel the pain caused by the food I ate at Khaibar, and at this time, I feel as if my aorta is being cut from that poison.“
The Mubahalah, Quran, and hadith all prove Muhammad was a false prophet.

Information from Sunni sources about the Fatima incident that caused her to get miscarriage and eventually died (apart from numerous shia sources):

1. “It is stated that Umar rushed (to the door of the House of Fatimah) and brought them forcibly while telling them that they must give their oath of allegiance willingly or unwillingly.”
-History of al-Tabari, English version, v 9, pp 188-189

2. “When Umar came to the door of the house of Fatimah, he said: “By Allah, I shall burn down (the house) over you unless you come out and give the oath of allegiance (to Abu Bakr).”
-History of Tabari (Arabic), v1, pp. 1118-1120 - History of Ibn Athir, v2, p.325 - Al-Isti’ab, by Ibn Abd al-Barr, v3, p975 - Tarikh al-Kulafa, by Ibn Qutaybah, v1, p20 - Al-Imamah wal-Siyasah, by Ibn Qutaybah, v1, pp. 19-20

3. “By God, either you come out to render the oath of allegiance, or I will set the house on fire.”Al-Zubair came out with his sword drawn. As he stumbled (upon something), the sword fell from his hand so they jumped over him and seized him.”
- History of Tabari, v9, pp 186-187

4. Umar asked for wood, and told those people inside the house: “I swear by Allah who has my soul in his hand, that if you do not come out, I will burn the house.”Someone told Umar that Fatimah was inside the house. Umar said: “So what! It doesn’t matter to me who is in the house.”
- Al-Imamah wa al-Siyasah by Ibn Qutaybah, v1, pp 3,19-20

5. Abu Bakr asked ‘Ali to support him, but ‘Ali refused, then Umar went toward the ‘Ali’s house with a burning torch. At the door he met Fatimah who said to him: “Do you intend to burn the door of my house?” Umar said: “Yes, because this act will strengthen the faith brought to us by your father.”
-Al-Ansab Ashraf, by al-Baladhuri, v1, pp 582,586

6. ‘Ali and Abbas were sitting inside the house of Fatimah, Abu Bakr told Umar: “Go and bring them; if they refuse, kill them.” Umar brought fire to burn the house. Fatimah came near the door and said: “O son of Khattab, have you come to burn our house on me and my children? Umar replied: “Yes I will, by Allah, until they come out and pay allegiance to the Prophet’s Caliph.”
-Iqd al-Fareed, by Ibn Abd Rabb, Part 3, Pg. 63
- Al-Ghurar, by Ibn Khazaben, related from Zayd Ibn Aslam

7. “They surrounded ‘Ali (as) and burned the door of his house and pulled him out against his will and pressed the leader of all women (Hadhrat Fatimah (sa)) between the door and the wall killing Mohsin (the male-child she was carrying in her womb for six months).”
- Abul Hassan, Ali ibn Al-Husayn
Al-Masudi, Isbaat Al-Wasiyyah

8. “On the day of ‘Bay’aat’ (paying allegiance), Umar hit Fatimah (sa) on the stomach such that child in her womb died.”
- Slahuddin Khalil Al-Safandi, Waafi
Al-wafiyaat

9. “During her last days, when Abu Bakr and Umar sought the mediation of Imam ‘Ali (as) to visit the ailing Hazrat Fatimah (sa), as quoted by Ibn Qutaybah, she turned her face to the wall when they greeted her and in response to their plea for appeasement reminded them of the prophetic declaration that one who displeases Fatimah (sa) has displeased the Prophet and finally said:”I take Allah and the angels to be my witness that you have not pleased me; on the other hand, you have angered me. When I shall meet the Prophet (S) I will complain about you two.”
- Al-Imamah wa al-Siyasah, by Ibn Qutaybah, v1, p14