Chinese police have detained 13 people in connection with a scaffolding collapse that left ten dead and two others injured in the northwestern city of Xi''an, a government spokesman said Wednesday. The scaffolding collapsed at a construction site in downtown Xi''an on Saturday morning as 12 workers fell to the ground from a height of 63.1 meters, the spokesman said. An initial investigation shows that workers had violated working regulations before lowering the scaffolding, China News Agency (Xinhua) reported. Altogether, 13 people in charge of the project have been detained by local police, he said. The Xi''an government has ordered a thorough inspection and overhaul of the city''s construction sites to crack down on illegal operations and eliminate safety problems.