Pretoria - A professor says there was no structural movement on the M1/Grayston Drive pedestrian and cyclist bridge before it collapsed."On the day of the collapse, photographs and videos were taken, but they didn’t show any structural movement prior to the collapse," said Professor Johannes Mostert, head of the department of the Materials Science and Metallurgical Engineering at the University of Pretoria."A combination of still photographs and video demonstrates that the initiation of the collapse was a significant displacement of the girders in an actual direction, together with the separation of the eastern and western assemblies at a later stage, followed by a downward rotation of the two assemblies and the collapse."Mostert was giving evidence at the inquiry into the structural collapse. A driver of a minibus taxi and a man in a Toyota Fortuner were killed during the collapse. Mostert told the commission that he had compiled a report from evidence he had gathered following the collapse.EvidenceREAD: Pedestrian bridge across M1 Grayston collapsesThe bridge over the M1 at Grayston Drive collapsed on October 14 2015."My mandate was to investigate and report on the features pertaining to the remnants of the collapse prior to during and after the removal from the collapse site and to consider their role in the collapse," he said.Mostert said he relied upon photographs and observations taken from the staff at the site of the collapse for his investigation. He added that he also used material from various people that were made available to him. He said he arrived at the collapse scene around 21:00 on the day of the collapse and only left the next morning after gathering the materials he would need."The starting point was to gain and understand the mechanisms of the collapse by referring to the location and features of various elements of the structure before, during and after the collapse. The photographs were taken before the collapse; as well as video taken during the collapse were used to establish the location of the elements prior to and during the collapse," he said.Mostert was asked to clear the confusion regarding what had actually collapsed on the day: Whether it was a temporary structure or a permanent structure/ bridge.He said the temporary structure was aimed at supporting the permanent structure while in the process of construction and it was that structure that had collapsed prior to the erection of the bridge."Temporary works is the overarching term and within it there is false work which is what we are dealing with in this particular case," he said.The inquiry continues.