MIAMI — A little girl who was digging a hole on the beach with her brother Tuesday afternoon at Lauderdale-by-the-Sea died when what began as a fun day in the sun took a tragic turn — the 5- to 6-foot deep hole suddenly collapsed, burying the siblings in the sand. Pompano Beach Fire Rescue paramedics, after digging them out of the sand on the beach at 4424 El Mar Drive, rushed the girl to the Broward Medical Center in Fort Lauderdale, where doctors pronounced her dead, according to the department’s spokesperson. Broward Sheriff’s Office deputies took her brother to the hospital in stable condi…