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.

The FBI’s Houston field office is “aware of an incident” that took place around July 23 aboard the Carnival Dream, the agency said.

Euvelester Villarreal Jr., 48, died aboard the Carnival Dream ship in the early morning hours last Wednesday, officials with the Galveston County Medical Examiner’s Office confirmed to MySA on Tuesday. Villarreal was a resident of Rio Grande City, the county seat and largest city in rural Starr County in the Rio Grande Valley.