When Xerxes understood the calamity which had taken place, he feared that some of the Ionians might advise the Hellenes, if they did not think of it themselves, to sail to the Hellespont and destroy the bridges. He would be trapped in Europe in danger of destruction, so he resolved on flight. He did not want to be detected either by the Hellenes or by his own men, so he attempted to build a dike across to Salamis, and joined together Phoenician cargo ships to be both a bridge and a wall, making preparations as if to fight another sea battle. All who saw him doing this confidently supposed that he fully intended to stay and fight there, but none of this eluded Mardonius, who had the most experience of the king's intentions. While doing all this, Xerxes sent a messenger to Persia to announce the disaster.