On August 4, 2020, Beirut experienced a large explosion when 2750 tons of ammonium nitrate detonated in the Beirut port resulting in more than 220 deaths, 76 000 injuries, 300 000 people displaced, and 15 billion dollars loss in property damage. Hôtel-Dieu de France (HDF), one of the largest university hospitals in the capital, has an emergency department that typically accommodates 25 patients. On that night, it received the largest number of injuries and had to accommodate more than 700 casualties within a few hours of the blast. This article describes HDF’s preparedness, emergency response, as well as the distribution of admissions to the emergency department, operation rooms, and the general ward. Surge capacity and the triage system are also detailed.