Forensic report has revealed LPG leak to be behind the blast at an eatery here in the heart of the city on July 18 which killed one man and injured 13 others.

The impact of the blast which took place at Himachali Rasoi restaurant, located in Middle Bazaar adjacent to the fire brigade office, was such that it shattered windowpanes of several shops in the vicinity.

The report put to rest speculations of sabotage as no remains of explosive material were found.

An examination of evidence collected from the blast site and adjacent places concluded that an LPG leak led to the blast, as per the experts of State Forensic Science Laboratory in Junga, SP Shimla Sanjeev Kumar Gandhi told PTI on Sunday.

"Neither any fragments of exploding devices like detonator or timer devices were found at the blast site nor any evidence of high temperature as generally found in the blast, triggered with the help of detonator or explosive materials surfaced," the report said.

The SP said the two commercial cylinders police recovered from the spot were found to be leaking and one of them had minimal gas left.

When LPG mixes up with air or vapours it becomes deadly and causes aerosol blast, he said.

The eatery was in exclusive possession of the owner and his workers for more than 36 hours before the blast as maintenance work was under progress, and according to CCTV footage, no third person had any access to the premises of the 'Himachal Rasoi', he said.

Liquefied Petroleum Gas is a highly flammable and sensitive mixture of many compounds of butane and propane extracted from hydrocarbons.

A Special Investigation Team constituted to probe the blast will conduct investigation in consonance with the opinion of forensic experts and fix responsibility of those who were negligent, the SP added.

The preliminary investigation by police and the forensic department had also suggested that a gas leak in the chamber of the restaurant led to the blast, and so was claimed by those who survived the blast.

The intensity of the blast – which was heard miles away – had earlier led to speculations that it could be an act of some nefarious elements.

On July 23, a team of National Bomb Data Centre of the National Security Guard had visited the eatery to find out the cause of the explosion.

The team collected evidence and recorded statements of the injured.

Considering that the blast took place near the Police Control Room, the DGP Sanjay Kundu had earlier requested Additional Secretary, Counter Terrorism and Counter Radicalization Division (CTCR) of the Ministry of Home Affairs to depute the Post Blast Investigation (PBI) team of NSG to visit the place and do an investigation. Police have filed an FIR under charges of endangering life, causing hurt, and causing death by negligence under sections 336, 337, 304 A of the Indian Penal Code.

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