The Grenfell Tower fire "should not have happened" and police are determined to hold people to account for it, the officer leading the huge inquiry has said.
A senior Metropolitan Police officer said listening to the 999 calls made it difficult not to want to hold someone to account.
Speaking of the scope of the investigation, detectives said they were looking at all aspects of the fire including, but not exclusive to, the cladding, fire exits and the stay-put advice residents had been given.
Metropolitan Police Commander Stuart Cundy said: "We have identified over 60 companies and organisations that have had some involvement in either the construction, management or refurbishment of Grenfell Tower."
He added that extensive amounts of evidence had already been gathered, including four terabytes of data from one company, and 20 terabytes of CCTV footage - the equivalent of two million boxes of A4 paper and 5,000 feature length films, respectively.
Mr Cundy explained the investigation would look at all kinds of potential offences, ranging from the most serious - manslaughter and corporate manslaughter - right the way down to more low level crimes.
He said: "We believe that around 80 people lost their lives as a result of the fire, that quite frankly, should not have happened.
"You can't listen to the families and to the 999 calls and not want to hold people to account for a fire that should not have happened."
As well as looking at how the fire started and how it spread, police will also look at the role of all emergency services involved on the night.
The 650 firefighters and 300 police officers who attended the fire will be interviewed and form part of the investigation.
Police revealed that around 255 survivors escaped the Grenfell Tower blaze.
Giving an update on the inquiry, Scotland Yard said officers still believe that around 80 people are dead or missing.
Investigations have found that 350 people should have been in the Kensington tower on the night of June 14.
But police believe that 14 residents were not in the building.
Thirty-two victims have been positively identified, with 55 post-mortem examinations having taken place.
Detectives say that due to the damage caused by the 1000C fire, some bodies may never be identified.
According to investigating officers speaking at the briefing on Monday, the Grenfell Tower investigation is the biggest the Metropolitan Police has conducted outside of counter-terrorism operations.
Tenants illegally subletting flats in Grenfell Tower have been urged to come forward to allow emergency services to establish the true death toll from the blaze.
The Government has said no-one from the block would face charges for illegally renting out their flats.
It is feared the scale of the tragedy has not been captured by official figures due to many residents living in the building off the books.
The Home Office has already said it would not conduct immigration checks on survivors and those coming forward with information.
Due to the significant damage caused by the fire, police have been left with the painstaking process of sifting through debris which may include human remains.
The first phase of recovery involving dogs and bringing out identifiable body parts ended last week.
Detectives have consulted experts from Austria about "cutting-edge" technology that could be used to the help identify victims, and spoken to experts who were and still are involved in identifying 9/11 victims.
DNA may need to be taken from relatives to help identify some of those who died. They may also be asked details about fractures or anything else that may help.