Kevin McGrath was with 42 members of his extended family on a Labor Day cruise to celebrate his father's 60th birthday in 2023 when he vanished.
By all accounts, the 26-year-old Army veteran was in good spirits, enjoying karaoke and the ship's nightlife as the Carnival Conquest made its way from Port Miami to the Bahamas early that September.
Kevin was seen dancing into the early morning with family friends on the last night of the cruise. Then he didn’t show up for breakfast with his family the following morning, as the Conquest prepared to dock in Port Miami. Kevin's disappearance was made even more perplexing because he hadn't packed up any of his clothes, and his ID and passport were found in his room.
The fourth episode of "Somebody Knows Something," "Lost At Sea"," premieres Monday, Aug. 24 at 10 p.m. ET/PT on Freeform, and streams the next day on Disney+ and Hulu.
Host Kara Robinson Chamberlain, a true crime influencer, kidnapping survivor and former law enforcement officer, investigated the disappearance that sparked widespread attention and stirred up social media.
Kevin's parents, Debra and Sean McGrath, told Chamberlain that their son was usually prompt, and that they became frantic after learning the cameras hadn't spotted him leaving the ship. Carnival also had no record of him scanning his key card to leave the ship.
"I broke down crying, hysterical," Debra McGrath said. "You're praying that please let him just be hiding somewhere. And then you start thinking, what if somebody harmed him?"
Kevin's key card was last used to check into the room that he stayed in with his twin brother Andre at 3:30 a.m. Andre told law enforcement that he thought Kevin left the room around 5 a.m. to go for a walk. This was typical for Kevin, who was deployed in Syria for three months in 2018 and 2019 and found it difficult to sleep at times.
"He would go out at 2 a.m.," Debra McGrath told Chamberlain. "It could be storming outside, and he would still go out. He wouldn't want to talk about it either."
Kevin's ex-wife, Addison Thomas, said that for a time when they were together, Kevin was using LSD to deal with the stress from his time in the army. He was on probation at the time of the cruise, after pleading guilty to aggravated assault for threatening to kill his wife and kids in Tennessee in 2022.
"When I looked at him, he didn't look like the Kevin that I knew," Thomas told Chamberlain about the incident. "Like there was something up. I think it was like PTSD, like actually cutting into him."
Shortly after his disappearance, Thomas told TMZ she wasn't afraid of Kevin and still loved him.
Before going on the cruise, Kevin did not make a request to his probation officer to travel, violating his parole and causing investigators to speculate if he was attempting to flee.
"Another very important piece of information that we found out was that Kevin was talking with another person that night, saying that he was capable of jumping off the ship and actually swimming ashore if he needed to due to his background," Capt. Frank Florio, a Coast Guard sector commander, told Chamberlain.
Months later, Carnival showed law enforcement footage of what appeared to be a splash in the water. Officials concluded that the video did not offer conclusive proof that a person fell off the ship.
Another passenger on the cruise, Will Ford, told Chamberlain that around 4:30 a.m. to 5 a.m., he saw somebody's feet sticking out from under a stack of lounge chairs. Despite giving his account to the McGrath family, Ford said law enforcement never reached out to him.
Both Addison Thomas and the McGrath family still hope they'll find an answer about what happened to Kevin.
"I miss him, I really do," Thomas told Chamberlain. "Both as the person I was with, and as a father ... It just hurts, because [he] was [his daughter's] best friend."
Carnival did not respond to requests for comment about the case.
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If you have any information about this case, please call the Miami-Dade Sheriff's Office: at (305) 743-7433.