There were CCTV cameras installed at various locations throughout the plant. At the time of this investigation, the recordings in the CCTV server had been overwritten (which I was told could only keep the data for four days). I was provided with a copy of CCTV recording prepared by SVI. However, this digital record was without recording time and date. Reviewing of the recording provided indicated that in the initial stages of evacuation, no sign of fire / smoke was seen. Heavy smoke was seen at different locations when almost of the workers in the factory had evacuated.