Photos and video showed rescue crews searching through a pile of rubble under floodlights. Much of the building, one of several similar structures in the compound, remained standing.
China has sought to improve construction quality and industrial safety with the threat of prosecution, but accidents still occur as companies cut corners to save costs.
Aging infrastructure is also a growing problem, with gas line explosions a particular threat, along with weak adherence to safety standards for the handling of volatile chemicals.