there were 28 freight trains and seven passenger trains traveling on the Beijing–Shanhaiguan line in the affected area; seven freight trains and two passenger trains derailed due to derangement of the rails, mostly south of Tangshan where the line was built on loose alluvium, diluvium, and occasional stretches of loose sand. In many of these cases – and also similar cases northeast of Tangshan, and on the Tongxian–Tuozitou line east of Fengrun – the railway embankment slumped due to weak soils. In other cases the embankment held, but transverse compression of the rails caused them to buckle. Railway operations were further impaired by the loss of communications (including signalling) and water supply (for the steam locomotives), in both cases due mainly to collapse of buildings and loss of electrical power. However, the most serious damage, taking the most manpower and longest time to repair, was that involving bridges. Most difficult was where soft or liquefied soil allowed the bank to slide into the river, shifting the abutments. A more frequent problem was where an approach embankment subsided, typically leaving the rails suspended from the abutment. There were numerous cases where concrete piers and abutments were damaged due to inadequate design and construction; bridges that were strengthened following the Haicheng earthquake survived with only slight damage. It was observed that at intensity VII and above damage to the roadbed was correlated mainly with loose soil and a high water table. Conversely, bridges and rails in Tangshan City, built on dense soil with a deep water table, were largely undamaged even though subject to intensity XI shaking. Over forty-two thousand people were mobilized to quickly effect emergency repair of the railways. The Tongxian-Tuozitou line was opened for traffic on 3 August, single track of the Beijing-Shanhaiguan line opened on 7 August, and both tracks on 10 August, albeit at restricted speeds over temporary bridges and at other places where repairs were not yet complete. Death toll The official report claimed 242,769 deaths and 164,851 serious injuries in Tangshan, but when take into account the "missing", the injured who later died and the deaths in nearby Beijing and Tianjin, scholars accepted at least 300,000 died, making it the deadliest earthquake in China and among the top disasters in China by death toll. Unofficial estimates of the death toll varied widely, and generally lack a clear authoritative basis. Early reports One of the earliest