Officers questioned four Chinese men who were found removing 32 files from containers behind the collapsed building, a police official said.

Workers said poor-quality materials were used during construction by a Chinese developer as it sought to cut costs. Investigators also said they found substandard steel bars in the rubble.

This is the terrifying moment onlookers fled during an earthquake, stopping only to record the collapse of a Chinese high-rise building. Footage shows panicked locals running as tremors from a magnitude 7.