According to a preliminary investigation by the FWC, Ella fell in the ocean near Nixon Beach while being towed a mile from shore while waterskiing.
The beach is in Miami-Dade County 7 miles south of downtown Miami.
While waiting to be recovered by her boat, another boat struck her and fled the scene, officials said. Ella, who wore a life jacket, died from her injuries.
"The vessel that struck the victim is described as a center console boat with a light blue hull," Callender said. "It has multiple white outboard engines and may have blue or dark blue bottom paint.
The boat was last seen heading west from Nixon Beach, the FWC reported.
"We are heartbroken as we say goodbye to our beautiful niece, Ella," the girl's aunt, Cristina Mas Adler, of Coral Gables, posted in a tribute on Facebook Monday. "She brought so much joy, laughter, and love into our lives. I love you Ella Bella."
