At 6 pm., a detonation occurred on a re-distillation unit of a hydroxylamine manufacturing plant, causing the death of 4 persons and 58 injuries. The factory was completely destroyed : 9 buildings collapsed, 2 collapsed partially, 4 were destroyed by fire. Damage were recorded outside the plant in a 1.5 km radius : 2 buildings collapsed, 5 collapsed partially, 286 were damaged, together with 55 vehicles and machines. A high-voltage line was disconnected for several hours and a telephone line was damaged. The traffic on a nearby national road was stopped temporarily by smoke and harmful gas generated by the fire.

The process consisted in the reduced-pressure distillation at 50°C of a 50% aqueous solution of hydroxylamine, containing about 10 ppb of iron impurities. The re-distillation column was equipped with an emergency blow-down piping at the underside of the bottom circulation piping ; a block valve was installed just apart from the branching point, creating a dead-end from the branch to the block valve. Ferrous iron accumulated gradually and provoked the exothermic decomposition of the hydroxylamine solution concentrated at 80 % at the bottom of the column.