Investigators in Florida are looking into the death of a woman after an apparent fall down stairs aboard a cruise ship.

Officials at Royal Caribbean Cruises say the victim was a 47-year-old U.S. citizen but her name had not been released by Monday afternoon.

The incident happened early Monday aboard the Liberty of the Seas, which was just returning to Port Everglades from a four-night cruise that included a stop in Mexico. Passengers told the South Florida SunSentinel they heard an alert that something had happened near the ship's disco between 1 a.m. and 2 a.m.

A Royal Caribbean spokeswoman said its medical personnel responded but the woman died before the ship reached port.

The Broward Sheriff's Office and the medical examiner were looking into the death Monday afternoon.