Year in Pictures: 2001

September:
In their dizzying early moments, the attacks of Sept. 11 seemed a New York story — but when another plane struck the Pentagon an hour later, the whole nation was instantly at war. The strike at the command center of America's military machine claimed 184 lives among the men and women who defend their nation and fight its battles — not innocents, but soldiers who paid the ultimate price on the second front in a brand-new war.

• Photos: Remembering 9/11: Evolution of Ground Zero