Fifteen-year-old Ella Adler was a devoted student at Ransom Everglades High School, her father said, excelling on the debate team, dance team and performing in the musical Chicago just weeks before her death off the waters of Key Biscayne in May 2024.
A ballerina, Adler had dreamed of dancing in the Nutcracker, a dream she turned into reality, performing in the show with the Miami City Ballet more than 100 times.
On Monday, Carlos Guillermo “Bill” Alonso, the driver of the boat that hit and killed Ella Adler, pleaded guilty to two misdemeanors in connection with the crash. The Coral Gables man was sentenced to 12 months of probation as part of a plea agreement approved by Miami-Dade County Court Judge Julie Harris Nelson. The offenses carried a maximum penalty of 60 days in jail, Nelson said.
Carlos Guillermo Alonso is sworn in before pleading guilty in MIami-Dade County court, Jan. 5, 2026, to misdemeanor boat safety charges related to the death of Ella Adler in 2024 (KBI via Miami-Dade Courts)
“Ella was extraordinary. She radiated joy, kindness and creativity in every room she entered. She was a devoted daughter, a beloved sister and a fierce and loyal friend,” her father Matthew said in a statement read in court. “Her life was filled with love, laughter, dance and meaning. Ella didn’t just live. She danced through life.
Adler was wakeboarding with friends on May 11, 2024 near the Nixon Beach Sandbar off Key Biscayne celebrating her birthday. She and another 15-year-old girl had fallen and were in the water when Alonso struck Adler with his 42-foot Boston Whaler, killing her. The other girl was not hurt.
Adler, of Miami Beach, was the granddaughter of Michael Adler, the then U.S. ambassador to Belgium.
As part of the deal, conditions of Alonso’s probation include that he attend a 75-hour boating safety course, make a $5,000 contribution to the Florida Crime Victims Compensation Fund in memory of Adler, pay a $500 state fine and court costs.
During his probation, Alonso will also be prohibited from driving a boat.
But Alonso will be allowed to have his probation terminated after six months, if he successfully completes all the court’s conditions. At that time, he will also be allowed to petition the court to have Monday’s guilty pleas vacated.
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Matthew Adler’s statement was read on behalf of the entire family, members of which were sitting in the quiet courtroom Monday, as Alonso watched from a separate table.
Matthew Adler, the father of Ella Adler, reads a statement to the court,Jan 5, 2026 (Miami-Dade Courts via KBI)
“Ella made everything more joyful, more beautiful and more connected. Our lives were centered around Ella,” Matthew Adler said.
At one point, the father spoke to Alonso directly, acknowledging the profound impact the fatal boating accident has had on his own life.
“That doesn’t lessen the devastation this has caused. Our daughter is gone and our family is shattered. We believe in accountability and also in humanity,” he said.
But Matthew Adler also addressed the need for improved boating safety in South Florida, calling for common sense regulation, better training and better enforcement.
“Too many children are dying on our waterways. Imagine if someone proposed eliminating driver’s license insurance or accountability on the roads. It would be unthinkable, but that is the reality every day on the water.”
Edmund Richard Hartley, the driver at the helm of the yacht that was towing Adler at the time of the accident, is still facing charges of careless operation and violations of navigation rules relating to lookout, responsibility for collision, and action to avoid collision.
Jessica De Leon is a general assignment reporter at the Key Biscayne Independent.