Following a tank explosion, 1,200 tons of beet molasses spread over the ground and then into the Le Mau river. One week later, the pollution became concentrated near a lock on the Marne Canal. Thousands of fish were found dead, yet 3 to 5 tons could be saved by transfer into the Marne River. A neighbouring and similar tank was drained as a precautionary measure. A metallurgical examination revealed a poor-quality tank (cracked welds, lack of a chamfer). The low concrete walls of the retention basin were not able to resist the flow pressure. The eventual tank rupture was likely due to a pressure surge subsequent to molasses fermentation coupled with vent obstruction. Storage was removed from the site.