At 11.40 a. m. the attack was launched in a heavy fog. It had been planned that the first stroke should take in the quarries of Haudromont, the height to the north of the ravine of La Dame, the intrenchment north of the farm of Thiaumont, the battery of La Fausse-Côte, and the ravine of Bazite. In the second phase, after an hour's stop to consolidate the first gains, the French troops were to press on to the crest of the heights to the north of the ravine of Couleuvre, the village of Douaumont, the fort of Douaumont, the dam and pond of Vaux, and on to the battery of Damloup.
The French attack succeeded in carrying out the first phase of the plan with insignificant losses, and proceeded almost immediately to advance to the second objective. "At 2.30 p. m.," said a French eyewitness of the attack, "the fog lifted and the observers could see a magic spectacle. It was our soldiers, filing like so many shadows along the crest of Douaumont, approaching the fort from all sides. Arriving at the fort, they quickly established themselves within, and through field glasses could be seen the long column of prisoners as they filed out.
"The French Fourth Regiment, charged with taking the quarries of Haudromont, went beyond their objective, which was the trench of Balfourier. The division under General Guyot de Salins had taken Thiaumont and Douaumont, while that of General du Passage had seized the wood of Caillette and advanced to the heights of La Fausse-Côte.
"Steadily foot by foot the French infantry pushed on, driving the enemy before them and taking 3,500 prisoners on the way, till at last after a severe struggle around Fort Douaumont they shot all of its defenders who refused to surrender and won it back to France."
In the space of four hours the French had recaptured territory which had taken the Germans eight months to conquer at a cost of several hundred thousand of their best troops. The Germans explained their defeat on the ground that the fog hampered their observation and barrage, while the French artillery had set fire to a store of benzine in the fort, which forced the garrison to evacuate.
In addition to the fort and village adjoining, the French forces captured the Haudromont quarries which had been in possession of the Germans since April 18, 1916.