Nebuchadnezzar"s many horses would raise much dust and cause a loud commotion as they breached the walls, entered the city, and trampled the streets of the mainland town. Many people would die, and Tyre"s strong pillars would fall. The pillars may refer to the leading inhabitants of the town and or to the prominent pillars in the temple of Melkart there (cf. 1 Kings 7:15). [1][source]
"Nebuchadnezzar destroyed mainland Tyre ..., but not the island stronghold. However, other evidence indicates that the island surrendered to Nebuchadnezzar in573-572 B.C." [2][source]