After spending most of the day in fruitless attempts to parley with the rebel force, Nicholas ordered a cavalry charge by Her Sovereign Majesty Empress Maria Theodorovna's Chevalier Guard Regiment that slipped on the icy cobbles and retired in disorder. Eventually, at the end of the day, Nicholas ordered three artillery pieces to open fire, with devastating effect. To avoid the slaughter, the rebels broke and ran. Some attempted to regroup on the frozen surface of the river Neva to the north. However, they were targeted by the artillery and suffered many casualties. As the ice was broken by the cannon fire, many sank. The revolt in the north came to an end. There was a rumor that during the nighttime operation of police and loyal army units to clean the city and Neva river many of the dead, dying, and wounded had been cast into Neva.