John Bacon

USA TODAY

Cuba began its formal farewell to revolutionary leader Fidel Castro on Monday with 21-gun salutes and a commemoration of his life in Havana's Plaza of the Revolution.

A broad swath of emotions were on display in the island nation 90 miles off Florida as some mourned, some expressed little interest and others worried about what a Donald Trump-led United States would mean for Cuba.

”It was Fidel that led the Revolution and took important steps to eradicate illiteracy, promote health and education," Manuel de Jesús Catalá Balón, a Guantánamo resident, told the Cuban state publication Granma. "Today will be remembered with sadness.”

Thousands of Cubans filed Monday through a memorial at the plaza where a nine-story image of a young Castro towered. The revolutionary died Friday at 90, almost a decade after illness forced him to transfer power to his brother Raúl.

Tania Jimenez, who arrived at 4 a.m. carrying a rose, was one of the first in line. “Fidel is everything to us, the soul of this country who gave everything, all his life,” said the mathematician, 53, amid tears.

Yankemell Barrera, a 20-year-old student, was not so moved by Castro's passing. Barrera told the Associated Press that Fidel Castro never played an important role in his life: Studying, he said, would be a better use of his time than attending memorials.

“Even if I’m obligated to go, I’m not doing it,” Barrera told AP.

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Yaneisi Lara, a 36-year-old Havana street vendor, told Reuters she was concerned about her country's future. Concerned enough to consider moving to the United States, she said.

The U.S. severed ties with Cuba in 1961 in opposition to Castro's communist regime, but two years ago President Obama ordered full restoration of diplomatic ties. On Monday, the movement toward normal relations continued when the first regularly scheduled flight from the U.S. to Havana flew out of Miami.

Trump, however, tweeted that "If Cuba is unwilling to make a better deal for the Cuban people, the Cuban/American people and the U.S. as a whole, I will terminate deal."

"With 'El Comandante' gone, I am a little fearful of what could happen because of Trump's way of thinking and acting," Lara said. "He could set back and block everything that's been going on, all the things Obama has done. And he did a lot, managing to get the U.S. closer to Cuba."

Also Monday, the first commercial flight from the U.S. to Havana in more than 50 years landed in Cuba. Passengers burst into applause as the American Airlines plane touched down, and Cubans saluted the jet by spraying water from firetrucks as it taxied along the runway at Jose Marti International Airport

The new flights were a result of warmer relations between the countries and were in place before Castro's death.

“It was very emotional for me,” said Jonathan Gonzalez, 31, a Cuban-American born in Miami who said it was his third time visiting the island.

Cuba's Council of State declared a nine-day Duelo Nacional, a national mourning period, which began Saturday. On Monday, a 9-story-tall picture of a young Castro looked out over the plaza in Havana. Tens of thousands of Cubans were expected to visit the square Monday and Tuesday to pay homage to Castro and "sign a solemn oath" to carry on the revolution that propelled Castro to power in 1959.

Castro's cremated remains then will begin a trek around the island nation before burial Sunday in Santiago, where Castro began his political and military ascension in 1953.

While Cuba mourns, few tears were being shed for Castro in Miami, home to thousands of Cuban refugees and exiles. Marcelo Cuba told the Miami Herald he was a political prisoner of Fidel Castro for more than five years in the 1980s. Cuba, who now lives in Homestead, Fla., said he attended Mass on Sunday because Castro's death marked a new chapter in his life.

“It took too long for Fidel to die, but I guess something is something and I have to celebrate, celebrate the death of that tyrant,” Cuba, 80, told the Herald. “And when Raúl dies I’ll come (to Mass) again.”

Contributing: Associated Press