A fire broke out at around 4:15 a.m. inside a container loaded with lead-acid batteries in a special cell fitted with a protective liner at a waste collection site. The smoke and flames set off the fire alarm, but the private security firm’s cameras did not pick up anything out of the ordinary. The firm contacted the on-call night manager and dispatched a security officer to the site. Hearing a crackling noise, the security officer alerted the fire brigade at 5:05 a.m. When they arrived 20 minutes later, the fire-fighters saw that the flames had spread to a second container. They extinguished the fire at around 6:00 a.m. Both containers were removed from the building and placed on a retention system.

On 15 March, the operator sent both the 1,294-tonne container that had caused the fire and the absorbent material used to recover the extinguishing water (0.345 tonnes) to a hazardous waste treatment plant and informed the inspection authorities for classified facilities. The fire had been quickly contained for several reasons: the facilities were well designed (waste isolated in a specific, lined cell), the fire was detected early and the fire-fighters had a good understanding of the site’s layout because they had conducted two visits a few months earlier.

The cause of the fire was autoignition of the wall of the first container due to overheating from contact between the terminals of the batteries stored in the container. Cables that had been left connected to the batteries increased the risk of contact between the terminals. The operator now requires that all battery cables be removed before batteries are placed inside the containers provided.