The 2008 Universal Studios fire that wiped out the Back to the Future courthouse square and a mechanical King Kong also destroyed thousands of original recording masters from some of the most influential artists of the 20th century.

Although the fire itself was in public knowledge, the loss of Universal Music Group’s (UMG) recordings was kept secret, with even the artists affected unaware of the extent of the damage. However, according to legal and internal documents seen by The New York Times, UMG put the number of music tapes destroyed when flames reached Building 6197 at about 175,000.

The irreplaceable master tapes originated from several labels, including Decca, MCA, ABC and Chess, and featured songs from jazz greats Louis Armstrong, Billie Holiday and Ella Fitzgerald, to rock n' roll architect Chuck Berry to the earliest material by Queen of Soul Aretha Franklin. Other masters lost in the flames include music by B.B. King, Joni Mitchell, Iggy Pop, Tom Petty, Sonic Youth, No Doubt, Snoop Dogg and Soundgarden.

The destruction of master tapes contradicts official statements at the time, including from a Universal spokesperson who told Billboard "we had no loss," adding that the company had recently moved "most" of the stored material on the movie lot to other facilities. In other statements of that time, the company admitted that some of the physical items were lost but the digital copies were already made for them.

Other groups, who believe to store their original records with UMG at that time, reacted in social media, admitting the loss of the music. hen asked by a fan, former Nirvana bassist Krist Novoselic said that some of Nirvana’s music is probably just gone forever.

The Roots’ tapes were also destroyed in the fire, and Questlove, who is the drummer and joint frontman for the Grammy-winning band has noted that some of their records cannot be found in any vaults or storages, and it is only now he knows why.

Steely Dan were also affected, and their manager Irving Azoff has released a statement on behalf of the band to Variety. “We have been aware of ‘missing’ original Steely Dan tapes for a long time now,” he says. “We’ve never been given a plausible explanation. Maybe they burned up in the big fire. In any case, it’s certainly a lost treasure.”

The UMG is currently disputing the severity of the damage as detailed in the New York Times piece. According to a statement from the company, the article contains “numerous inaccuracies, misleading statements, contradictions and fundamental misunderstandings of the scope of the incident and affected assets.”

“Music preservation is of the highest priority for us and we are proud of our track record,” the statement reads in part. “While there are constraints preventing us from publicly addressing some of the details of the fire that occurred at NBC Universal Studios facility more than a decade ago, the incident — while deeply unfortunate – never affected the availability of the commercially released music nor impacted artists’ compensation.”