It's now been a little over 16 years since the 9/11 attacks that saw plans flown in the World Trade Center in New York City. The memory of those tragic moments lives on, and we've gathered some powerful and rarely-seen photos to help us remember just how terrible these attacks were. May we never forget the innocent people who lost their lives that day.

Bystanders look up in shock and confusion as one tower begins to fall.

Patrick Witty

A photographer snapped this shot just instants before one plane hit.

Rob Howard

This heartbreaking photo shows some people who preferred to leap out of the windows rather than stay in the building.

David Surowiecki

People flee as smoke and debris pours towards them.

Kelly Price

A photo taken from an apartment a few blocks away.

Patricia McDonough

Some people just got on with their work; the shock of what was happening hadn't even sunk in.

Melanie Einzig

These panorama shots show one of the planes approaching and striking the tower.

The south tower crumbles.

James Nachtwey / VII for Time

Another shot of the collapse of the south tower.

Bolivar Arellano

This mom-to-be posed for a photo, having no idea what was about to happen in the background.

Daser Bessler