Urwah bin al-Zubayr narrated that a man was bringing Sayyidah Zaynab bint Rasulullah (peace and blessings be upon him) when two men of Quraysh went after him, fought him and seized her from him by force, and pushed her so that she fell on a rock; she miscarried and bled heavily. They took her to Abu Sufyan. Then the women of Banu Hashim came, and he handed her over to them. After that she came as an emigrant (to Madinah), but she remained in pain until she died of that pain, and the people regarded her as a martyr.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19256