India, Sept. 11 -- A quarter of a century after four hijacked aircraft turned an ordinary September morning into one of the defining tragedies of modern history, the memory of September 11, 2001, remains deeply embedded in the United States and far beyond its borders.

The attacks killed 2,977 people, excluding the 19 hijackers, and transformed global security, foreign policy, aviation, intelligence gathering and domestic politics.

They also set in motion wars, surveillance programmes and political changes whose effects continue to be felt 25 years later.

For families who lost loved ones, however, the anniversary remains deeply personal.

Jenna Jacobs McPartland was nine months pregnant when she learnt that a plane had struck the North ...