The horrific scene unfolded at the height of the morning commute when thousands of pedestrians are trying to get to work.
Video on Sky News showed wreckage burning in a street, and black smoke in the area. The video from the crash scene showed a line of flaming fuel and debris. Witnesses said the helicopter hit a crane atop a 50-story residential building, the St. George Wharf Tower.
Allen Crosbie, site manager for the landscape firm Maylim company, who was working at the scene, said the explosion convinced him and others that London was being attacked.
