2 Missing in Lake Near Fla. Legoland After Boating Accident During Couple's Anniversary Celebration

Polk County Sheriff's Office

Two men are believed to have drowned in a boating accident on a lake near the Legoland theme park in Florida, authorities said.

Jeffrey Marrero was joined on the boat by Velcky Velasquez and her boyfriend, Orlando Ortiz, to celebrate the couple's one-year anniversary of being together, when Velasquez, 38, jumped into the lake with the boat's anchor to secure the vessel, though it began to float away "due to the wind and heavy chop to the water," the Polk Couty Sheriff's Office said in a news release.

Velasquez, who was later discovered by police after Marrero's daughters called 911, was found treading water near the boat. She told authorities that Marrero and Ortiz, 32, jumped into the water to help her, but they were not strong swimmers and ended up going underwater.

Marrero's daughters, ages eight and 10, were alone on the vessel — a 16-foot Tahoe ski boat —when they were discovered, police said.

The lake is now set to be closed until their bodies are found, according to the Polk Couty Sheriff's Office.

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In a press conference after the incident, Sheriff Grady Judd said Velasquez was "just very inexperienced," adding, "She thinks you're supposed to get into the water, put the anchor in, and then tie it to the boat."

Conditions on the water were rough, he noted, with two-foot white caps and 20 mph winds. Judd also described the two men who are believed to have drowned as "average swimmers."

Deputies who responded to the 911 call placed by Marrero's daughters were helped by a man at the lake's edge who was launching his fishing boat.

Together, the group raced to the scene, which is when they found Velasquez, and then rescued the two sisters, returning them to shore before beginning a larger search for the missing men.

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Judd said the young girls who called 911 had saved the woman's life. "The children ... are obviously upset because they saw all of this unfold right before their eyes," he noted.

The sheriff also said the two men are now believed to be dead. "We have every expectation that they have perished in the water by drowning," he said at the press conference.

A search to find their bodies will include the PCSO Marine Unit and FWC using side scan sonar, and Seminole County deputies using their underwater drone, according to a police statement.

Lake Eloise is adjacent to the Legoland Florida Resort, but is not a part of the theme park. A statement from Legoland, shared with PEOPLE, said the incident "is not connected with us in any way" and officials were using a boardwalk at its hotel as a command center.

"Our thoughts and prayers are with the family during this difficult time," the statement added.