At 3:45 am at a chemical site, an isobutane leak occurred on the flange of a temperature sensor, positioned at the apex of a small-diameter absorption column. A fire sparked by the lightning bolt broke out. The cone formed reached a length of several metres. The plant was shut down and the Internal Response Plan (POI) was activated. Despite considerably cooling the affected zone (1,500 m3/hour of water), the fire continued to be fuelled for another five and a half hours by the pressurised gas; it was eventually extinguished at 9:45 am. Column depressurisation was completed at 3:40 am and the emergency notification was lifted at 2:50. Activation of the response plan enabled eliminating the explosion risk for the overheated capacitances containing gas. The accessory equipment was not damaged, and the incident resulted in no victims or environmental damage.