There were no casualties during the Battle of Fort Sumter. The only Union casualties reported happened during the evacuation of the fort, where one solder was killed and one mortally wounded by an accidental explosion during a planned 100-gun salute.
After South Carolina seceded from the Union on Dec. 20, 1860, U.S. Maj. Robert Anderson moved his 85 troops into Fort Sumter on Dec. 26, fearing for their safety. On April 11, 1861, Confederate Brig. Gen. P.G.T. Beauregard sent aides to demand the fort's surrender. The next morning, Confederate cannons opened fire on the fort. The attack lasted 34 hours before Maj. Robert Anderson surrendered. However, the Confederates allowed him one final 100-gun salute per the terms of surrender, which resulted in the only casualties of the battle.