MGM Resorts International announced Wednesday that an Illinois lab was working to determine why a 12-year-old male dolphin named "Beetle" died the morning of Oct. 27 in Siegfried & Roy's Secret Garden and Dolphin Habitat. MGM Resorts spokeswoman Yvette Monet says Beetle appeared ill days before his death and had been closely watched by members of the habitat's 50-person staff which includes a full-time veterinarian.