The tombs beneath Ground Zero

As New York gears up for the tenth anniversary of 9/11, this footage, taken by rescue workers, shows the eerie scenes in the basements beneath the wrecked skyscrapers. Workers from the Federal Emergency Management Agency (FEMA) spent eight months documenting the scene in Lower Manhattan as they searched the six storeys beneath the complex.

Guided by periodic shafts of light, rescue teams made their way through the pitch-black as they searched for survivors. None were found. While some staircases remained down into the basements-cum-tombs, most of the pathways and escalators were blocked by debris, forcing rescuers to travel along pipes and squeeze through narrow gaps in the rubble.