A sizeable crowd stood in the rain for half an hour waiting for proceedings to start.
A man in a Tavern Snacks van drove along and scraped the entire length of one car, also dragging along the back of an expensive looking pickup just in front of it. The people around me ooh-ed and aah-ed as the driver of the van ploughed on, at last emerging form the rear of the van with his own cameraphone to take pictures of the damage and apply a note to the cars.
Once, a couple of years ago, I was skiving in Soho - just wandering around, drinking coffee, playing pinball, looking in shop windows. I was not far from Seven Dials. A van roared past me then, narrowly missing hitting some people across from me. I gasped, tutted and walked on, when, around a corner, I suddenly heard loud raised voices. The van was stopped, at an angle to the pavement with its driver's door wide open. Next to it the driver was approaching a pedestrian angrily.
"You're a maniac," the pedestrian said, "You could have killed me!" Without warning, the driver lunged forward and made to stab the other guy in the eye with a pen he was holding. He landed a glancing blow, and the pedestrian backed off hurriedly. One of his companions half-heartedly said something to the van driver, who was like a raging bull, and tried to stab the other man again. I remember that the van driver was wearing glasses, because they flew off during his first frenzied attack, and they lay on the ground unheeded after that. I was still walking towards the fight, and I could see the crazed look in the van driver's eyes. It looked as if things were going to turn very nasty. Then another passer-by leapt into action. He barged into the van driver and grabbed him around both arms, pushing him to one side.
"If you're going to stop a fight," he said, "Fucking stop it! No point fannying around!" That seemed to do the trick. The driver picked up his glasses and stalked back to his van. The guy who had been attacked, bleeding from one of the pen wounds, was consoled by his ineffectual mate and I carried on walking.
The crowd cheered and clapped as the artwork beneath was slowly revealed - the pieces of the sculpture covered with photographs from Nick Knight. I later discovered that the installation also features a heartbeat sound, clearly audible from the bridge over the Channel 4 Drum.