ABC NEWS SPEAKS EXCLUSIVELY WITH MAN RESCUED AFTER WEEK LOST AT SEA DURING WHICH HIS MOTHER DIED

'Lost at Sea' airs on '20/20' Friday, January 27 on ABC

A tragic accident or foul play? It was a story that made national headlines, and on Friday night, ABC News Correspondent Linzie Janis speaks exclusively to Nathan Carman about his rescue from the ill-fated fishing trip that claimed his mother Linda's life. Nathan claims it was an accident that sunk his fishing boat, but authorities are still investigating the circumstances of her disappearance. On September 17, 2016, Nathan and Linda left a Rhode Island marina sailing far out to sea to fish for tuna. When they did not return the Coast Guard sent out a search team. Seven days later a freighter rescued Nathan from a small life raft, but Linda was nowhere to be found. Nathan claims that after the boat made a "funny" noise, began to take on water and started to sink, he was not able to find his mother and he never saw her again. Janis' report also includes interviews with Captain Zhao Hengdong, captain of the freighter that rescued Nathan; psychologist Dr. Rebecca Sachs; Captain Dave McCormick, who is familiar with the Rhode Island marina; Mike Iozzi, a regular visitor to the area and more. "Lost at Sea" airs on "20/20," FRIDAY, JANUARY 27 (10:00-11:00 p.m., ET) on ABC.

Nathan told "20/20" that conditions were good the day they set out to sea, but McCormick, who says he was out on the same waters hours before, disagrees. This is not the first time Nathan was the last person to see a family member before their questionable death. Three years earlier Nathan was the last person to see his grandfather John Chakalos before he was shot and killed. Authorities were suspicious of Nathan at the time, but no charges were ever filed. Nathan claims that he is innocent and that he was not responsible for the death of his mother or grandfather. He believes that because he has Asperger's syndrome, which is on the autism spectrum, he is being misunderstood and targeted.

"20/20" is anchored by Elizabeth Vargas and David Muir. David Sloan is senior executive producer.