Firefighters and helicopters fight to contain the fire at a tank farm in Cuba

Helicopters and firefighters fought Tuesday to contain a day-old fire at a tank farm in Cuba that has already destroyed four tanks and threatened four others.

The fire, which broke out on Friday after lightning struck one of the tanks, left a 60-year-old firefighter dead and 14 colleagues missing, according to authorities.

More than 100 people were reported injured, with 22 still hospitalized.

About 5,000 people were evacuated from the disaster area on the outskirts of Matanzas, an industrial city of 140,000 people about 100 kilometers west of Havana.

As teams prepared to try to put out the blaze with foam on Tuesday, fears that the blaze could threaten fuel supplies to thermoelectric plants grew as Cuba already battles power outages.

Four military helicopters repeatedly flew over the depot, dropping seawater on the fire.

“Fire crews continue to clear a path to the blaze to allow teams tasked with applying the foam to get to the site,” Matanzas Gov. Mario Sabines said on Twitter.

He added that smoke from the fire had reduced visibility to near zero and drones were being used to provide better visibility.

Four of the eight tanks at the scene have already collapsed in the blaze, spilling their contents and still burning, according to deputy fire chief Alexander Avalos Jorge.

Water was sprayed on the remaining four tanks, which were only 150 meters (about 492 feet) from the other four tanks, to keep them cool.

The tanks each hold around 50,000 cubic meters or 50 million liters of fuel.

Built in the 1980s and modernized several times, the Matanzas depot supplies the Antonio Guiteras thermoelectric power plant, the largest in the communist country.

The facility has five docks for vessels up to 180,000 tons and can process 40,000 barrels per day.

The big question now is “the fueling of thermoelectric plants,” said Jorge Pinon, a Cuban energy policy expert at the University of Texas.

“The problem with the (power generation) was not the lack of fuel, but the plants are very old and have maintenance problems. Now they will also lack fuel,” he said.

“If they lose Matanzas, they lose the ability to power the power plants,” Pinon said.

The disaster comes at a time when the island — with an aging power grid and persistent fuel shortages — is facing growing difficulties in meeting energy needs.

Since May, authorities have imposed power outages of up to 12 hours a day in some regions – sparking protests across the country of 11 million people.

Thirteen flights have arrived from Mexico and four from Venezuela carrying technicians, firefighters and equipment including fire retardant foam, fire hoses, helicopter water buckets, spray pumps and medicines.

A logistics support ship from the Mexican Navy arrived in Matanzas Bay on Tuesday with a helicopter on deck.

And Cuba’s Deputy Foreign Minister Carlos Fernandez de Cossio thanked the United States – which has maintained sanctions against the communist nation for six decades – for offering “technical advice”.