Q. I understand that we are not supposed to bury more than one body in a single grave. What are we supposed to do when there are massive deaths, such as in times contagion like we are currently facing?
A. According to Shafii texts, including Imam al-Nawawi’s Minhāj al-tālibīn and its many commentaries and derivatives, two bodies should not be buried in the same grave unless there is a need to do so. Some commentators (including Ibn al-Mulaqqin and Ibn Qadi Shuhbah) following Imam al-Nawawi’s lead in Sharḥ al-muhadhdhab clarify that this need is met when there are large enough deaths from contagion or a collapsed structure that it becomes difficult to bury each body in a separate grave. When that need has been met, two, three, or more can be buried in the same grave. They also mention that unrelated men and women should not be buried in the same grave unless there is an emphatic need. Among the evidence for burying more than one body in a single grave is that the Prophet ﷺ buried the martyrs from the Battle of Uḥud in pairs [i.e., two in each grave] (Bukhari, 1343).
This answers the question concerning whether it is permissible when there is a large number of deaths. Questions related to whether the conditions have been met and how it should be done need to be directed to local Shari’ah and medical experts.
And Allah knows best.
Sources: al-Nawawi, Sharh al-muhadhdhab, 5:284; Ibn al-Mulaqqin, Ujālat al-muḥtāj, 1:440; and Ibn Qadi al-Shuhbah, Bidāyat al-muḥtāj, 1:442. cf Ibn Hajar, Tuḥfat al-muḥtāj, 3:173–4; al-Khatib al-Shirbini, Mughni al-muḥtāj, 2:40; al-Ramli, Nihāyat al-muḥtāj, 3:10–11.