Dr. Mahmoud and his entire family were martyred as a result of a direct strike on their home in Rafah, to which his children and their families were displaced. Dr. Mahmoud was martyred alongside his wife Raja' (Um Tamer), his son Dr. Tamer al-Khayyat with his wife Dr. Razan and their daughter Rose, his son Basel al-Khayyat with his wife Hadeel and their children Elyaa, Seleen, Mahmoud and 2-month-old Mohammed, and his daughter Hiba al-Khayyat with her four children Omar, Benan, Jenan, and Elyaa. They had fled to their grandfather's house in search of safety. The only survivor of the strike that killed 18 members of her family was Dr. Tamer's infant daughter Miral.