Without warning, an Israeli air strike destroyed the four-storey building in the Gaza Strip where Dr Ayman Abu al-Ouf lived early on Sunday.
The doctor, who was head of internal medicine at the Palestinian territory’s main hospital, was killed along with 12 members of his extended family.
They included his mother and father, his wife Reem, and their 17-year-old son Tawfik and 12-year-old-daughter Tala.
“This is a really big loss not just for us personally because we knew Ayman – this is also a loss for his patients and students,” Dr Ghaith al-Zaanin, a close friend and former colleague who lives in Canada, told the BBC.
As well as being in charge of internal medicine at al-Shifa hospital in Gaza City, Dr Abu al-Ouf oversaw its response to the coronavirus pandemic.