The coffin was supposed to contain Jack's deceased father, Christian. Jack was originally not allowed to bring the coffin on the plane as he lacked the proper documentation. Jack pleaded with the Oceanic Airlines ticket agent, Chrissy, saying that he had the funeral all set up and needed to get his father on the plane so it could all be over. Jack found this coffin near the entrance to the caves. Jack found it closed, and opened it expecting to find his father, only to find it empty. He then broke it to pieces with a metal pipe. ("White Rabbit")