At least three people were killed on Tuesday after a fire and explosion occurred underground at the hydroelectric power plant owned by Enel Green Power, part of Enel Group, in Bargi, about 80 km (50 miles) from Bologna.
"The rescuers' hope is always to find people alive. The scenario we see does not make us believe much in these hypotheses, but I repeat that we are also accustomed to miracles," fire brigade's spokesperson, Luca Cari said on Wednesday.
Cari said that the situation was very difficult, due to the water rising quickly inside the power plant, which was built underground on one of the banks of Lake Suviana.
The rescuers were working mainly with divers, but they still did not have details on the potential causes and the dynamics of the accident, he added.
The power plant had been undergoing efficiency works, which Enel Green Power entrusted in 2022 to three primary companies, Siemens Energy, ABB and Voith, Enel's subsidiary said in a statement.
"From what has been reconstructed, the testing of the first generation group had already been completed in the past days and, at the time the accident occurred, the testing of the second group was underway," Enel Green Power said.
The CEO of Enel Green Power, Salvatore Bernabei, went immediately to the site on Tuesday, the company said, adding it would fully collaborate with the relevant authorities to ascertain the facts.
The power station has a capacity of 300 megawatt (MW), part of Enel Group's 13,000 MW of total hydroelectric capacity in Italy.