 Before surrendering, the French commanders had ordered the breechblocks of the 155mm cannons thrown into a river to prevent the Japanese from using them.During the Sino-French War of 1884–1885, the French had been forced into an embarrassing retreat from Lạng Sơn in which equipment had likewise been thrown into the same river to prevent capture.When the breechblocks of 1940 were eventually retrieved, several chests of money lost in 1885 were found also.