Corrosion of steel brackets and piling of additional weight allowed by the Brihanumbai Municipal Corporation led to the partial collapse of a Road Over Bridge (ROB) here earlier this month, a railway probe report has found. The preliminary inquiry report by Sushil Chandra, Commissioner of Railway Safety (CRS), Western Circle, attributed the mishap to "failure of Railway staff and others". Union Railway Minister Piyush Goyal had ordered an inquiry after a portion of Gokhale Road Over Bridge near the suburban Andheri station collapsed on July 3, killing one person and crippling the movement of trains. A press note issued by the CRS' office said the probe found that civic officials allowed extra load on the bridge in the form of various cables, sand, paver blocks and other materials, without the approval of Western Railway (WR). Chandra submitted his report to the WR authorities today, the last day of the deadline set by Railway Minister Piyush Goyal for submitting it. "The accident.occurred due to heavy\/deep corrosion and pitting of cantilever steel brackets supporting the pathway resulting in thinning down of section.," said the report. "Additional load of various cables, sand, paver blocks etc provided by the BMC without prior permission from the Western Railway", not contemplated when the bridge was designed, also contributed to its weakening, it said. A senior WR official said they would await a detailed report before deciding on preventive steps. When contacted, a senior BMC official, speaking on the condition of anonymity, expressed doubt as to whether additional load caused the collapse. "We have not gone through the report yet. But we don't think the additional load of wires and cables was the prime reason. We would present our side during a detailed probe," he said. After the bridge collapse, the railway minister, who visited the site, ordered a safety audit of over bridges and other railway infrastructure in the city by a joint team of WR, BMC and the IIT Bombay.