LONDON (AP) — A government-ordered inquiry into the London tower block fire that killed at least 80 people opened Thursday, with its leader acknowledging that survivors feel a “great sense of anger and betrayal.”

Retired judge Martin Moore-Bick said he hoped his investigation would “provide a small measure of solace” by answering how such a disaster could happen in 21st-century London.

The June 14 blaze began in a refrigerator in an apartment at Grenfell Tower before racing through the 24-story building. One aspect of the investigation will be the role of combustible aluminum cladding installed during a refurbishment to the 1970s tower block. Emergency safety checks have uncovered scores of other buildings across Britain with similar cladding.

The fire was Britain’s deadliest in more than a century, and provoked intense grief and anger. Many residents accuse officials in Kensington and Chelsea, one of London’s richest boroughs, of ignoring their safety concerns because the tower building was home to a largely immigrant and working-class population.

Moore-Bick said he was aware that “former residents of the tower and local people feel a great sense of anger and betrayal.”

“That is entirely natural and understandable,” he said. “But if the inquiry is to get to the truth of what happened, it must seek out all the evidence and examine it calmly and rationally.”

Moore-Bick’s inquiry will look at causes of the blaze, the response of local authorities and the country’s high-rise building regulations. But some survivors are critical because it will not investigate wider issues around social housing in Britain that many residents had wanted to include.

The lawmaker for the area, opposition Labour politican Emma Dent Coad, said the inquiry might provide “a technical assessment of what happened.”

But she said it would not get to the heart of “the bigger questions … all the ‘why’ questions that aren’t being answered.”

London police are conducting a separate criminal inquiry, and have said they will consider whether authorities committed corporate manslaughter.

Residents are also frustrated at the slow pace of the inquiry, which opened exactly three months after the blaze. Moore-Bick said he hoped to begin public evidence sessions by the end of the year and produce an interim report by Easter 2018.

He said “there are many potential witnesses still to be interviewed and many thousands of documents to be reviewed.”

“The scale of the task is enormous,” the judge said.