Collins et al. (2015:xxiii–xxiv) inferred from rebuilding patterns that Tall al-Hammam experienced a major earthquake that devastated the existing fortification system. They place this event at the transition from Intermediate Bronze 2 to Middle Bronze 1, between 2000 and 1950 BCE. According to Collins et al. (2015:xxiii–xxiv), the city was immediately rebuilt and refurbished after this event, much like the earlier Early Bronze 2/ Early Bronze 3 transition event (City Wall Earthquake 1). The Intermediate Bronze Age fortifications, which were themselves derived from earlier Early Bronze Age defenses, were still in use when the earthquake struck. The shock is described as having devastated the city between 2000 and 1950 BCE, probably damaging the perimeter defenses beyond repair ( Collins et al. 2015:xxvii). The earlier Early Bronze/Intermediate Bronze city wall—about 6 m thick and retained as part of the defensive system—no longer sufficed after this destruction, and the earthquake effectively marked the end of the old fortification scheme.

In the aftermath of the event, the city’s builders adopted an entirely new defensive concept. Rather than merely repairing the older walls, they constructed a large ramparted fortification system typical of the early Middle Bronze Age. This new system was designed to meet evolving methods of siege warfare, including siege towers, battering rams, and sapper attacks, and it paralleled similar developments across the southern and northern Levant around the beginning of Middle Bronze I ( Collins et al. 2015:xxvii). Thus, the Intermediate Bronze II/Middle Bronze I earthquake between 2000 and 1950 BCE appears to have caused extensive damage to the city’s perimeter defenses and triggered a major reorganization of the fortification system. As with the earlier seismic event at the Early Bronze II/Early Bronze III transition, the archaeological record indicates rapid rebuilding, but in this case the reconstruction took the form of a fundamentally new ramparted defensive complex characteristic of the early Middle Bronze Age ( Collins et al. 2015:xxiii-xxiv, xxvii). Dating appears to rely primarily on pottery evidence.