15 April 2013, Boston Marathon Bombing.
15 April 1989, Hillsborough Stadium disaster. At the start of an FA Cup semi-final, a crush on the steel-fenced terraces of Sheffield Wednesday's stadium resulted in the death of 96 Liverpool fans and left hundreds more injured. A large crowd entered a tunnel, but the way out of the tunnel had been blocked by a gate and the people at the front of the crowd were crushed against it by the pressure from the people at the back.
The images were brutal — contorted bodies pressed against what looked like the wall of a wire cage, elbows thrust against the bars at strange angles, faces bloated with unconsciousness or mad with pain and desperation.