In this paper, we present the closed U-ribs deteriorated case with steel plate deck of bridge in service. In the investigation, we carried out a desk study of the deck to through details and to identify if there are any details that have a track record of causing problems on other bridges. Defect identification, detailed inspection, finding causes and evaluation were also conducted. This case will contribute to prevent similar case in the future and the ongoing development of operational and maintenance procedures for the life of the bridge.