Their name conjures up the most celebrated moment of America’s post-Sept. 11 military campaigns. Now the Navy SEALs belong to a grimmer chapter in history: the most deadly incident for U.S. forces in the 10-year Afghanistan war.

Three months after they killed Al Qaeda leader Osama bin Laden in neighboring Pakistan and cemented their place in military legend, the SEALs suffered a devastating loss when nearly two dozen of the elite troops were among 30 Americans who died when their helicopter was shot down in Afghanistan early Saturday.

It was the largest number of American troops killed in a single day in the war. U.S. officials said the helicopter appeared to have been felled by enemy fire, and the Taliban quickly claimed responsibility. Seven Afghan commandos and a civilian interpreter also were killed, Afghan President Hamid Karzai said. . .