Great Tangshan Earthquake: An account of the anticipation of the great earthquake of 1976, and the steps that the authorities took in the preceding days. From the UN Global Programme.
SpiNet - 1976 Tangshan Earthquake: Describes the geology of the region, and the causes of the quake.
Tangshan - The Deadliest Earthquake: Brief account of the disaster, including the warning signs and the aftermath, from About.com.