What had caused this event? The police had received numerous calls from members of the public reporting gunshots on the underground and at street level, and had arrived within six minutes ready to respond. But the only violence that anyone had witnessed with their eyes was a scuffle on an overcrowded rush-hour platform, as two men bumped into each other, and a punch or two was thrown. While it remained unclear what had caused the impression of shots being fired, the scuffle had been enough to lead the surrounding crowd to retreat suddenly in fear, producing a wave of rapid movement that was then amplified as it spread along the busy platform and through the station. Given that there had been terrorist attacks in London earlier in the year and others reportedly foiled by the police, it is not hard to understand how panic might have spread in such confined spaces. Nobody would expect people to act in accordance with the facts in the heat of the moment, as a mass of bodies are hurtling and screaming around them. Where rapid response is essential, bodily instinct takes hold.