An explosion followed by fire occurred at a company specialised in maintaining gas cisterns and more specifically draining and degassing for a steady clientele. The company was testing a new accessory for a cistern suspended on a gantry crane equipped with a weight indicator. The tank, fitted with a valve at its base, was also connected to a flare, installed 15 m away to simulate an individual’s use of gas. At the end of filling, while the tank contained 1.4 tonnes of propane, the crane/tank assembly tipped over and collapsed. The valve beneath the tank was severed and product spread on the ground: a cloud formed and then ignited on the flare. The vessel being tested, caught in the blaze, heated and a BLEVE-type explosion (with domino effect) ensued. A neighbouring vessel exploded thereafter. Some 15 other cisterns were caught in the fire but none exploded, as was a buffer tank used to collect the drainage from cisterns and the lorry’s tanker. The accident’s toll included serious burns to the lorry driver as he was activating his vehicle’s emergency shutoff switch. First responders set up 5 water curtain nozzles, 1 high-powered variable-speed nozzle and another smaller hose to ensure the protection and cooling of adjacent cisterns. The Deputy Prefect visited the site and a 900-m safety perimeter was introduced. A few nearby dwellings were evacuated and residents remained confined in other homes. Property damage consisted of deterioration of the 2 stationary cisterns, the tanker lorry, tanks and 2 cars in the vicinity. Twenty houses were without electricity due to the degradation of a 15,000-V line. This facility, under SEVESO authority, was not compliant. The inspection authorities for classified facilities recorded these facts and proposed that the Prefect issue a suspension order.