According to a report from Game N Guide, it is possible that "Vikings" season 4 part 2 might see the end of Ragnar Lothbrok (Travis Fimmel). It is even stated he might die as early as season 4 episode 11, the premiere episode for the season's second half. 

The teaser trailer released during the recent San Diego Comic Con showcases Ragnar being imprisoned in a cage which is then being delivered by a cart somewhere far off. It is speculated that this could be the moment when Ragnar is captured and given to King Aelle (Ivan Kaye) as a gift, leading to the events of Ragnar's death. 

Norse legends state that Ragnar was executed by King Aelle when the latter tossed Ragnar into a pit filled with poisonous snakes. This might be the scene that will end Ragnar's life but the report also points out that his sons will eventually come around to avenge his death.

According to the report, Ivar the Boneless (Alex Høgh Andersen) will rally his brothers together and they will invade Northumbria, reaving and causing destruction in their path until they kill King Aelle for what he did to their father. This will also reportedly make Ivar one of the most feared Vikings in history.

It is also speculated that Ragnar's sons will not just be killing King Aelle but will carve the symbol of a blood eagle on him to complete their act of vengeance. From there the show has yet to reveal what Ragnar's sons might do next although it is heavily implied that at least one of them will cross the Atlantic Ocean and reach North America. 

History HD has yet to confirm or deny any of these rumors and it is still possible that Ragnar might live, at least until season 5 premieres and the show then shifts its focus on his sons. 

"Vikings" season 4 episode 11 premieres this fall.