Milan's mayor Beppe Sala has likened a fire in a tower block in Milan on Sunday to the Grenfell Tower fire in London due to the way the flames seemingly spread through its cladding.

The fire in the Torre del Moro apartment block, an 18-storey residential building in Milan, started on the 15th floor and first rose to the top of the building, before moving downwards in an "unnatural" path, reported Italian newspaper Corriere della Sera.

"The causes of the fire are still being investigated," Milan mayor Beppe Sala said in a post on Facebook.

"What became clear from the beginning, though, is that the exterior coating of the building went up in flames all too quickly, in a dynamic that closely recalled the Grenfell Tower fire in London a few years ago."

Fire reportedly spread through building's cladding

The 60-metre-high building was clad in materials including aluminium and polystyrene, Corriere della Sera said.

The fire, which begun on 29 August at around 5:30pm, engulfed the exterior cladding of the building, which burnt and fell into the street.

Despite the speed of the fire, all of the residents who were in their apartments when the fire started were safely evacuated.

"When we arrived, the fire had a normal course, that is from the 15th floor upwards," a firefighter told Corriere della Sera.

"When the first team entered, the tower was immediately engulfed in flames and the fire went down unnaturally, as evidence that it found in the lining not only non-fireproof material but also fuel capable of extending the fire quickly."

#Milano #incendio grattacielo: fiamme sotto controllo, le nostre squadre stanno avanzando dall’interno verso i piani superiori dell’edificio. Sono 15 i mezzi impiegati, oltre 50 i #vigilidelfuoco. Immagini della ricognizione aerea dall’elicottero. [#29agosto 20:00] pic.twitter.com/dKtm1eznUi

— Vigili del Fuoco (@emergenzavvf) August 29, 2021

Milan emergency services try to put the fire out

Authorities fear the high temperature of the fire could have melted the building's steel columns, meaning there is a risk it may now collapse, reported The Guardian.

The cause of the fire in Torro del Moro and the speed with which it spread is currently under investigation.

Deputy prosecutor Tiziana Sicilano, who is coordinating the investigation into the fire, said remains of the cladding panels "burned like cardboard".

According to Corriere della Sera, the inner lining of the cladding panels on the building's facade would have "acted as gasoline".

Additionally, some of the building's tenants said the fire-fighting system inside the building might also have failed, with residents saying that "vents" between the tenth and fifteenth floors did not deliver water.

Tower only ten years old

The tower was completed in 2011, leading the mayor to question how the fire managed to decimate the building so quickly.

"My hope is that responsibilities will be quickly ascertained," Sala said. "The Torre del Moro was built a little over 10 years ago and it's not acceptable that such a modern building proved completely vulnerable."

The Grenfell Tower fire in London in 2017, which killed 72 people, spread through the building's cladding system and trapped residents inside. An official inquiry into the disaster is still ongoing after it was paused due to the coronavirus pandemic.

The Grenfell Tower fire started a discussion around dangerous cladding materials used for high-rises in the UK, with the Royal Institute of Britsh Architects criticising the government for its "naive" decision to only fund the removal of Grenfell-style cladding on housing over a certain height.

Top photograph is by Piero Cruciatti via Getty Images.