On 4 July 1898, the 9th Massachusetts Volunteer Infantry were guarding the prisoners of war inside "Harvard". A guard ordered a prisoner, who was attempting to cross the line, to return. The prisoner did not understand English and the guard fired a shot causing other prisoners to stand up. Fearing the prisoners were about to attack, the guards opened fire killing six prisoners and wounding thirteen more. After the investigation, it was concluded that it was a mistake. The tragedy was known as "Harvard Incident".