The fire started at around 7:30 p.m. on 2 August 1973 when approximately 3,000 people were inside, and was caused by three boys who were smoking in a small disused kiosk, on the centre's miniature golf course and who told police it was likely started by a carelessly discarded match or stub. The burning kiosk collapsed against the exterior of the building. This part of the building was clad in a material called "Galbestos": profiled steel sheeting with asbestos felt on both sides coated with bitumen, with no fire-resistant qualities. The fire spread to the wall's interior soundproofing material, which was highly combustible, causing an intense fire that ignited the flammable acrylic sheeting that covered the rest of the building. The fire quickly spread across the sheeting on the leisure centre walls and roof, and through vents which were not properly fireproofed. The acrylic material melted, allowing more oxygen to enter, and dropping burning molten material, both starting other fires and injuring those trying to escape. The building's open-plan design included many unblocked internal spaces that acted as chimneys, adding to the conflagration.