On September 11, 2001, hijacked airliners struck the World Trade Center and the Pentagon, killing 2,977 people — and the world that followed was not the world that came before.
It began as a clear Tuesday morning in New York. It ended with two of the tallest towers on earth reduced to dust, a burning gash in the Pentagon, a field in Pennsylvania — and 2,977 dead. Nothing about the twenty-first century would be negotiated afterward; everything would be shaped by it.