Averil Cameron says Lactantius records that Constantine had a dream the night before battle where he was told to place the chi-rho (a symbol of Christ) on his soldiers' shields. Eusebius, however, makes no mention of such a vision. Eusebius compares the battle to the triumph of Moses over Pharaoh at the Rea Sea since Maxentius and his soldiers "sank as lead into the mighty waters" as the Book of Exodus says of Pharaoh. Bardill says the two armies met at the Saxa Rubra as Constantine approached the capitol from his camp. Maxentius' troops were forced back to the Tiber river where Maxentius had destroyed the bridge in hopes of trapping Constantine's troops. They would have been forced to cross the Tiber on the remaining pontoons, but it was Maxentius who was trapped instead. Maxentius drowned when the pontoons came apart.