 The accident occurred during the 500cc race when the leader Carlo Bandirola was being followed by Les Graham and Bell.When Bandirola braked early for the La Source Hairpin, a collision occurred when the AJS Porcupine motorcycle ridden by Graham hit the rear-wheel of motorcycle ridden by Bandirola.Although, Graham was thrown clear, Bell hit the AJS Porcupine and machines collided at high speed with a timing-post at La Source Hairpin.