Drone display recreates the Twin Towers over New York Cityhttps://www.bbc.co.uk/news/videos/cx2z7x57gjeo
Organisers say each of the 2,977 drones in the display represents a victim of the 9/11 attacks.

Organisers say each of the 2,977 drones in the display represents a victim of the 9/11 attacks.
