A day after two research scientists in the Radiation and Photochemistry Department of the Bhabha Atomic Research Centre (BARC) were killed in a fire in their laboratory, the postmortem report concluded that the bodies had 100 per cent burns due to a chemical explosion, followed by a fire. The lab was full of vapours and the open chemical bottles could have reacted, leading to the explosion and fire. Preliminary inquires indicate that the explosion could have been triggered by chemicals like benzene and acetone, bottles of which may have been kept open in the lab. Additional Commissioner of Police (East Region) Ritesh Kumar said that samples are being sent for forensic tests. Lab staff and eyewitnesses who reported the fire have recorded their statements. A dog squad was also brought in to check for any explosive material. According to the postmortem report, the bodies bore no other injury marks. Blood, DNA and viscera samples have been sent for forensics. Bone marrow samples of victims were preserved to match with the DNA of the parents to make a confirmed identification. The bodies were handed over to the families on Wednesday night. Said Director of Forensic Science Laboratories, Kalina, M V Garad: