The brother of an American citizen killed in a brazen boat clash with Cuban forces says his sibling was consumed by an "obsessive and diabolical" push to free the island and that "no one knew" what he was planning.

American citizen Michel Ortega Casanova, who worked as a truck driver, was one of 10 passengers on a Florida-registered boat that allegedly opened fire on Cuban soldiers in an attempt to infiltrate the island.

A Monroe County Sheriff's Office incident report obtained by Fox News noted the boat's owner reported it stolen Wednesday after hearing about the Cuba shootout on the news.

The owner, who did not speak English, told deputies his 24-foot vessel went missing, and he suspected an employee named Hector — who had two young daughters in Cuba — may have taken it.

Ortega Casanova, who lived in the U.S. for more than two decades, was one of four killed in the attempt. He is survived by his wife, mother, brother, two sisters, daughter and unborn grandchild.

Six other passengers, all Cubans living in the U.S., were injured. It is unclear if Hector was on board.

Ortega Casanova's brother, Misael, told acts of terrorism," according to the government.

Cuban politician Bruno Rodriguez Parrilla posted to X after the incident, claiming a "rigorous investigation" is being conducted to clarify the facts.

"Cuba has had to face numerous terrorist and aggressive infiltrations originating from #EEUU since 1959, at a high cost in lives, injuries, and material damage," Rodriguez Parrilla wrote in a post. "The defense of Cuba's coasts, of the national territory, and of national security is an ineludible duty."

Rubio said the U.S. will verify the facts independently, and the U.S. Department of Homeland Security and U.S. Coast Guard are investigating.

Vice President JD Vance said he was briefed on the incident, and the White House is monitoring the situation.

"Hopefully it’s not as bad as we fear it could be," Vance said.

Florida’s Attorney General James Uthmeier said prosecutors will work with federal, state and law enforcement partners to start an investigation.

"The Cuban government cannot be trusted, and we will do everything in our power to hold these communists accountable," Uthmeier wrote in a social media post.

The Associated Press contributed to this report.