Johannesburg - Concerns were raised about the safety of the Grayston bridge a few days before its collapse, a commission of inquiry heard on Tuesday.While all of the key players involved in the planning and building of the bridge over the M1 in Johannesburg have declined to comment on who was responsible for the collapse of a temporary scaffolding structure, it was on Tuesday revealed that there had been concerns about the project before the collapse. Speaking at a commission of inquiry probing the collapse that killed two people and left 19 injured, Siyabonga Genu, a senior development manager at the Johannesburg Development Agency (JDA) said concerns about a missing set of bolts were raised in a meeting a few days before the collapse. "At the meeting, which included representatives of Form Scaff [the company that supplied the scaffolding], the issue of the missing set of bolts was discussed. However, Murray and Roberts assured those present at the meeting that the missing bolts would not affect the structural integrity of the temporary bridge," Genu said.The structure collapsed on October 14, just days later, leaving two people dead and 19 others injured as their vehicles were crushed by the structure. Advocate Ewan Rudolph, representing Form Scaff, said that during this meeting, their representative had pointed out that the girder beams had been misaligned but they were assured that all the safety checks had been done. Rudolph said they were also concerned that Murray and Roberts would not be ready to receive the temporary structure which Form Scaff had already constructed on its own premises.Rudolph said this assumption was fueled by the fact that the eastern embankment had not been excavated and leveled in preparation to receive the structures.Just days before that, Form Scaff had also found that Murray and Roberts had deviated from the final drawing that it had earlier handed to Form Scaff.Just like all the other key players, namely Murray and Roberts, the JDA and engineering consultancy firm Royal Haskoning DHV, Form Scaff denied responsibility for the collapse. Form Scaff said it was not responsible for the design of the temporary structure.The other parties are still to be questioned by the commission which is scheduled to resume on April 19.