Today, different ways are suggested to help elderly people in case of emergency. Our aim here is to propose a novel method, without any wearable device, to detect falls on the floor with a multiple cameras system. This proposal uses image analysis to localise people and reconstruct their 3D shape and position. The particularity of this contribution is the use of cameras sharing a large common field of view. Experimental results obtained with 14 different fall scenarios and 14 normal daily activities showed a 100% fall detection efficiency.