At around 9:30 at an LPG refilling centre, 12 tonnes of propane leaked from the valves of three full horizontal storage tanks of 150 m3. This occurred while an outside company was replacing a metal gangway straddling four tanks. The crane operator had trouble lifting the dismounted tank he was handling and increased the lifting power. This caused the gangway to suddenly disconnect and start swaying, so that it collided with the valves. During the process the crane operator, a subcontractor of the outside company handling the work, was guided by two people. The site was secured and the automatic sprinkler system was activated. The internal operating plan was launched at 9:45; the rescue services were alerted and gas detection measures reinforced. A security perimeter was established and three neighbouring buildings occupied by members of the police force and their families (150 people) were evacuated. Traffic on the N193 was interrupted, which affected access to the airport and caused disturbances for 50% of passengers at boarding. Firemen regularly measured the amount of combustible and explosive gases at and outside the site.

The liquid phases of LPG are emptied by fire trucks and dispatched to the clients. LPG was transferred between the storage tanks in question gradually as the valves of each tank were being replaced after they had been put under atmospheric pressure. As valves needed to be delivered for the repair of the third tank, it was taken out of service. During the emptying phase, the walls of the retention troughs and the related compressed air networks broke under pressure from the water accumulated during the sprinkling of the tanks; when the bleed valves lost their air supply, they closed automatically and consequently the transfer of propane was stopped until the personnel could restore the network.

Road traffic was re-established at 21:30 once the situation was under control. The internal operating plan was lifted at 5:30 the next morning and the rescue services finished their work at 6:30. On 25 May, a specialised company carried out non-destructive testing on the tanks to verify that there were no cracks.

While the rescue services were at work, the motor of one of the two seawater pumps supplying the fire fighters overheated after being used non-stop for 18 hours and due to blockage of some of the suction strainers. Despite a loss of efficiency, the water supply to the fire main remained sufficient. The freshwater pump was used as a backup. The operator will examine which work procedures need to be implemented or changed (permit for crane work, working at heights, etc.). It plans to carry out the work on tanks filled up to the minimum level or at least to perform operations manually.