How did cole and alison son die?

He did get sucked into the ocean they rushed him out Alison being a nurse at the time pumped his chest he threw up a lot of water he was tired and she gave him a bath put him to bed and he drowned in his sleep. Secondary Drowning. Lungs still had water very very sad I cry every time it's told.

Gabriel got swept up in the ocean and his lungs filled with water. Alison pumped his lungs and he woke up and seemed fine but tired. Alison took him home and put him to bed even though Cherry told him to take him to a doctor. Gabriel still had water in his lungs and never woke up. This is a terrible phenomenon called "dry drowning" or "secondary drowning." Basically, the leftover water prevents the lungs from transferring oxygen to the rest of the body even though the person is awake and appears to be functioning. It wasn't Alison's fault because most people don't know about dry drowning and she didn't understand the signs. But she beats herself up about it because she could have taken him to a doctor.