S1·E1 part 1

In part 1, a vacationing Brit named Susie Carter is diving off the coast of Khao Lak, Thailand when, to her horror, she encounters a floating corpse. After a few disoriented minutes, she is retrieved by her diving boat. As more bodies float by, the boat heads to shore – and its passengers see for the first time that Khao Lak has been wiped out. Once the group is safely on shore, Susie and the others search for their loved ones, but rush to higher ground out of fear that another wave will hit. Trying to determine the fates of loved ones while fighting to stay alive under extreme circumstances, these and other characters are tested in ways, physical and emotional, that they could never have imagined.