Passengers on the ship told said they woke up to the sound of sirens at around 3 or 4 a.m. Wednesday, and one heard a request for medical assistance on one of its decks, according to KHOU.

An FBI investigation is underway after an incident on a Carnival Dream cruise ship based out of Galveston, Texas, according to multiple reports. KHOU cites law enforcement sources, who claim there is a "death investigation.

GALVESTON, Texas — The FBI is looking into allegations of a sexual assault aboard a Carnival cruise ship out of Galveston. According to the FBI, it happened aboard the Carnival Breeze. At this point, it’s not clear exactly when the incident took place.