(Reuters) — A fire at dawn on Friday in a nursing home in Milan left at least six dead and some 80 injured, including three in critical condition, according to Italian authorities.

The fire started in a room on the first floor of the center. It quickly extinguished and did not spread to the rest of the building, but produced a large amount of toxic fumes.

Two residents were burned to death in their bedroom, while four others died of poisoning, Milan Mayor Giuseppe Sala said in press statements at the scene.

“It could have been (even) worse. That said, six deaths is a very high toll,” Sala said, noting that the facility housed 167 people.

Fire department spokesman Luca Cari said the cause of the fire was under investigation, but added it was likely accidental.

Firefighters intervened in the residential center “Hogar de los esposas”, located in the neighborhood of Corvetto, in the southeast of the city, shortly after 1 a.m., time (7 p.m. Miami time, this Thursday).

Some 80 people were evacuated, many of them in wheelchairs, while another 80 were taken to hospital, local fire chief Nicola Miceli told public television RAI.

Miceli described the rescue operations as “particularly difficult” due to thick smoke, which limits visibility, and the fact that many residents could not stand unaided.

Lucia, a local resident, said she saw some of them “panting” at their windows, wearing rags over their faces to protect themselves from the smoke.

He said the rescue teams “were wonderful” at helping everyone. “Those who could walk, they walked out, those who couldn’t, I think they walked out on their sheets.”