The companies that worked on the Grenfell Tower refurbishment killed 72 people “as sure as if they had taken careful aim with a gun and pulled the trigger”, the public inquiry into the disaster has been told by lawyers for the bereaved and survivors.

After three days of submissions from the corporates, which the inquiry’s lead counsel described as a “merry-go-round of buck-passing”, the survivors said on Thursday they were “genuinely shocked at corporates seeking to defend the indefensible”. They said: “All have blood on their hands.”

Timeline Key events since the Grenfell Tower fire Show The fire breaks out in the early hours of the morning, prompting a huge response from emergency services, who are unable to bring the fire under control or prevent a severe loss of life. The then Conservative prime minister, Theresa May, visits the scene and orders a full inquiry into the disaster, and the government promises that every family will be rehoused locally. The communities secretary, Sajid Javid, orders an emergency fire safety review of 4,000 tower blocks across Britain, and it will emerge that 120 tower blocks have combustible cladding. Scotland Yard launches a criminal investigation into the Grenfell fire. The chancellor, Philip Hammond, says the cladding used on Grenfell Tower was banned in the UK. The retired judge Sir Martin Moore-Bick is appointed to lead the public inquiry. Kensington and Chelsea council’s first meeting since the disaster is abandoned after the council fails in a bid to ban the media from attending. Survivors have their first official meeting with the police and coroner. The inquiry formally opens. As the final death toll is confirmed to be 71 people, it is revealed that hundreds of households are still living in hotels. In defensive testimony at the inquiry, London fire brigade commissioner Dany Cotton said she would not change anything about the way the brigade responded to the Grenfell disaster, provoking anger from both survivors and the bereaved. Grenfell survivors and the bereaved expressed frustration at Scotland Yard after they admitted no charges were likely until 2021. The public inquiry report concludes that fewer people would have died had the fire brigade been better prepared. Leader of the House of Commons Jacob Rees-Mogg is forced to apologise after stating that victims of Grenfell did not use "common sense" and leave the burning building. Grenfell cladding firm Arconic reveals it has spent £30 million on lawyers and advisors defending their role in the disaster. The second phase of the Grenfell Tower inquiry begins. Stacee Smith and Grace Mainwaring

Evidence was presented that the global companies that made the Grenfell Tower cladding materials marketed their products in the UK despite knowing they were highly combustible. They specifically targeted Grenfell, it was claimed.

Stephanie Barwise, representing around 280 of the bereaved and survivors, revealed an internal email from the insulation manufacturer Celotex in which an executive admitted to a distributor it was “clearly wrong” to think it was OK to use combustible insulation on buildings of any height.

Rob Warren, the head of technical at Celotex in Ipswich, said: “The fire hasn’t got a tape measure and if it starts at the ground floor it will love to race up.”

The distributor, Martin Stearne at SIG Technical Services in Bedford, replied: “Never has the expression smoke and mirrors been more appropriate. I think I’ll adopt a version of caveat emptor [buyer beware] and if specifically challenged use the rock fibre options [ie non-combustible]. If I’m not challenged it’ll be RS5000 [Celotex’s combustible insulation].”

Celotex had an aggressive marketing strategy and used distributors as “pushers”, Barwise said. Grenfell was on a “must-win projects list” sent by Celotex to its parent company, Saint-Gobain, on 7 November 2014.

Arconic, the US firm that made the combustible cladding panels, also specifically targeted the Grenfell Tower project as part of an attempt to double its sales in the UK in 2014. At the time it was being prevented from selling in Europe, where fire regulations were stricter, Barwise said.

“Armed with the knowledge that its product was at best class E [combustible], and increasingly could not be sold in other markets, Arconic set out to increase sales in the UK market and win the Grenfell Tower project,” she said.

In April 2016, while works on Grenfell were ongoing, Arconic was sent guidance stating that UK building regulations required “all significant elements of each and every layer of the wall to be non-combustible or of limited combustibility”.

“Yet Arconic failed to advise any of the contractors or designers with whom it had been dealing on Grenfell that the polyethylene cored Reynobond was unsuitable and non-compliant,” she said.

Sam Stein QC, representing other bereaved and survivors, said: “Those companies involved killed when they criminally failed to consider the safety of others. They killed when they promoted their unsuitable dangerous products in the pursuit of money and they killed when they entirely ignored their ultimate clients, the people of Grenfell Tower. They knew they were literally playing with fire,” he said.

Adrian Williamson QC, for a third group, said the Royal Borough of Kensington and Chelsea was “at the heart” of the disaster. He revealed how the council’s director of housing, Laura Johnson, reported in 2013 that Grenfell Tower was worth so little to its property portfolio that anything spent on it was, in Williamson’s words, “money down the drain”.

In July 2013, Johnson said Grenfell was “one of the poorer performing assets in the housing stock with a net present value over 30 years of -£340k. Any additional investment will effectively increase the negative NPV on a pound-for-pound basis.”

Williamson also revealed an email from Peter Maddison, director of assets and regeneration at the tenant management organisation (TMO), who said: “Value for money is to be regarded as the key driver of the [Grenfell] project.” Internal emails showed the switch to the combustible aluminium cladding from zinc was for the sake of cheapness, he said.

Barwise said the TMO had a “complacent attitude to fire”. It removed fire door closers inside the tower, and its fire risk assessor was “careless” and made a flawed assessment of the consequences of a fire. It did not produce required personal evacuation plans for disabled residents. Its failings “contributed to the loss of life”.

The fire engineer Exova produced five reports on fire safety strategy, all of which were “fundamentally flawed”, she said. It was negligent in its assurance in November 2013 that the “proposed changes will have no effect on the building in relation to external fire spread”.

It knew at that time that metal composite cladding was being used that had to worsen the condition of the existing solid concrete walls.

There was “a culture within Exova … to play down potential non-compliance in order to get around the building control officer,” Barwise said. One of Exova’s employees acknowledged in an email that the proposals for the smoke ventilation system amounted to “making an existing crap condition worse”.

The inquiry also heard fresh anger about Wednesday’s threat by some of corporate participants not to give evidence if it would be later used in criminal proceedings.

Barwise said on Thursday that the application by the architects Studio E, current and former staff at the main contractor Rydon, the TMO and Harley Facades for an undertaking that nothing they said would be used to further a prosecution against them seemed to be “sabotaging the inquiry”.

“The behaviours of arrogance and complacency which caused the disastrous fire at Grenfell still rage unchecked in many of the core participants,” she said.

Stein said his clients were “furious” at the move. They are “outraged by an application which has all the appearance of looking like an attempt to pull a fast one,” he said. “Do the companies who have made this application still not understand? Do they still have no respect, no regard and no feeling for the people who have lost so much.”