Brazilian football was in mourning on Friday after 10 people died when a fire ripped through a youth training facility at the country’s most popular club, Flamengo, authorities said.

The pre-dawn blaze in Rio de Janeiro hit a building that housed players aged 14 to 17, firefighters said.

Rio’s Deputy Governor, Claudio Castro said “preliminary information indicates there were young players and staff” amongst the dead.

The SporTV channel said the victims included six players and four members of staff.

Distraught relatives rushed to the facility seeking information about loved ones, TV footage showed. Most of the youth players at the club are not locals but come from all over the country.

In addition to the deaths, three people were injured.

The cause was not immediately known, but local newspaper Extra said witnesses alleged the fire started in the air conditioning system.

“It’s the worst tragedy in the club’s 123 years,” said Flamengo president Rodolfo Landim, who visited the scene.

“Flamengo is in mourning,” the club wrote on its social media accounts.

Brazil’s President Jair Bolsonaro, who is in semi-intensive care in hospital following surgery on his abdomen, said he felt “the families’ pain.”

In a statement shared by the presidency, he added that he was dismayed by “this tragedy… which has taken the lives of young people who had started the journey towards realizing their professional dreams.”

Brazil’s Pele, widely regarded as the best player to ever live, said: “It’s a very sad day for Brazilian football.”

The country’s biggest current star Neymar, who plays for Paris Saint-Germain in France, posted a picture on his Instagram account of the Flamengo club badge with the words: “My sympathies.”

– ‘Let’s pray’ –

Teenage Real Madrid forward Vinicius Junior, who came up through the youth ranks at Flamengo before signing with the European Champions in 2017 for 45 million euros ($51 million), posted a message on Twitter asking people to pray for the victims.

“Just by thinking about the days and nights I spent in the training center gives me goose bumps,” said the 18-year-old.

“I still can’t believe it. Let’s pray for everyone.”

Globo TV broadcast aerial footage of the fire, which it said had been brought under control after it burned for two hours.

The blaze broke out at 5:00 am in the Vargem Grande district of Rio in a modern facility where the top-flight professional Flamengo squad also trains, the news website G1 said.

The fire brigade said in a statement that the center was “in the process of” meeting fire safety standards but did not yet have a certificate of approval.

The main team had been due to practice at the same facility later in the morning, for their last training session ahead of Saturday’s derby against fierce local rivals Fluminense.

The Rio de Janeiro football federation said it had called a meeting between the two clubs’ management to discuss postponing the match.

Fluminense, the most popular club in football-crazed Brazil, was among a number of clubs that sent messages of condolence on social media.

– They came from afar –

Youth league teams also train at the facility, known as Ninho do Urubu, which means “the vulture’s nest.”

Brazilian football legend Zico, a former Flamengo player, described the incident as a “tragedy.”

Felipe Bornier, the Rio state sports secretary, told journalists that “we must absolutely give all the support necessary to the victims’ loved ones because most of them aren’t from Rio.”

The training camp is in an area of western Rio that was hit by a fierce storm on Wednesday night. Six people were killed.

Because of those heavy rains the football facility remained without electricity or water on Friday as the fire broke out, G1 reported.

It’s only two years since Brazilian football was in mourning over an airplane disaster that decimated the Chapecoense team. The team’s plane crashed in Colombia killing 71 people, including 19 players, 14 members of staff and around 20 journalists.